Chris Masterjohn, PhD shares an ultimate resource of Vitamin K2
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If there’s a single vitamin you need to know more about, it’s vitamin K2. The first reason is you’re probably not getting enough. The second is that it doesn’t get the attention it deserves, and it’s really hard to find reliable and easy-to-use information about it.

This resource is meant to change that. It begins by teaching you everything you need to know about the vitamin, including its benefits, how much you need, and how to get it from food. It includes shareable infographics to make the concepts fun and easy to understand. Finally, it provides reviews of the available supplements and a searchable database of the vitamin K2 contents of foods that can’t be found anywhere else.

If you’re a beginner, you can read the article straight through or pick the parts that are most interesting or useful to you. If you are an advanced user and already know a lot about vitamin K2 or have a strong science background, you can click on the buttons that say “click here for a more detailed explanation” in order to expand descriptions that are better suited to your level of expertise.

The Health Benefits of Vitamin K2

Vitamin K2 has a wide range of underappreciated health benefits:

    • It prevents calcium from going into all the wrong places and makes sure it gets into all the right places. For example, it keeps it out of your kidneys, where it  would cause kidney stones, and keeps it out of your blood vessels, where it would cause heart disease, but helps it to get into your bones and teeth, making your bones strong and your teeth resistant to cavities.
    • It helps you make insulin and remain very sensitive to insulin. This means it helps stabilize your blood sugar, protects against diabetes, and prevents the metabolic problems that often arise as a consequence of obesity.
    • It promotes sexual health by helping you optimize your sex hormones. For example, it increases testosterone and fertility in males, and it helps bring the high levels of male hormones found in women with polycystic ovarian syndrome (PCOS) back down to normal.
    • It helps improve exercise performance by enhancing your ability to utilize energy during bouts of physical activity.
    • It protects against cancer by suppressing the genes that make cells cancerous and expressing the genes that make cells healthy.

These roles are shown in the shareable infographic below. You can share it using the button in the upper right corner, or the buttons on the bottom strip. You can even use the button in the upper right corner to generate an embed code to share it on your own site if you have one.

Click here for a more detailed explanation.
Click the buttons below to read more about the biochemistry that underlies these health roles, or the evidence supporting their relevance in humans.


The Biochemistry Underlying the Health Benefits of Vitamin K2

Vitamin K-dependent 𝛄-Carboxylation

Vitamin K2‘s best-known and most well-established role is as a cofactor for the vitamin K carboxylase. This is a role that it shares equally with vitamin K1. The difference between vitamins K1 and K2 is discussed below, and in this section I will simply refer to “vitamin K.”

The vitamin K carboxylase is an enzyme that adds carbon dioxide to the side chains of specific glutamate residues within specific vitamin K-dependent proteins. Once added to a glutamate residue, the carbon dioxide becomes a carboxyl group, so the process is known as carboxylation. Carboxyl groups carry negative charges, so carboxylation helps vitamin K-dependent proteins bind to calcium, which carries a positive charge. In other words, the most well-established role of vitamin K is to add carbon dioxide to proteins and thereby give them the ability to bind calcium.

Since the carboxyl group is added to the third carbon of the glutamate sidechain, known as the gamma (𝛄) carbon, the process is known as 𝛄-carboxylation. Once modified in this way, glutamate becomes 𝛄-carboxyglutamate and is abbreviated “Gla.” Thus, vitamin K-dependent proteins often have the term “Gla” in their names.

The figure below shows vitamin K-dependent 𝛄-carboxylation in more detail.

A. The general structure of an amino acid, featuring a carboxyl group (COOH) on the right.

B. At the pH range that prevails within the human body, carboxyl groups often ionize, giving them a negative charge.

C. Glutamate. Moving from the central carbon through each carbon of the side chain, we label the carbons alpha (α), beta (β), and gamma (ɣ). Since the side chain carboxyl group is attached to the ɣ carbon, it is known as a ɣ-carboxyl group.

D. ɣ-carboxylation. The vitamin K carboxylase uses vitamin K as a cofactor to add carbon dioxide to the ɣ carbon of the glutamate residue side chain. This converts glutamate, abbreviated Glu, to ɣ-carboxylglutamate, abbreviated Gla. The second ɣ-carboxyl group gives the side chain a second negative charge, which improves its ability to bind to calcium, which carries a positive charge. Although ionic calcium is shown in the figure, some vitamin K-dependent proteins bind to calcium salts rather than calcium ions.

There are a wide variety of vitamin K-dependent proteins made in different tissues that fulfill different functions but that all undergo the same process of 𝛄-carboxylation. In each case, calcium-binding is essential for the protein’s activities. However, the role that calcium-binding plays is different for different proteins.

The Role of Vitamin K in Blood Clotting

We have known about the importance of vitamin K for blood clotting since the 1930s (Suttie, 2014). Blood clotting is regulated by a variety of proteins known as clotting factors that are all made in the liver and sent out into the blood, where they circulate in inactive form until blood vessel damage makes clotting necessary. In the clotting factors, vitamin K-dependent 𝛄-carboxylation allows calcium to serve as a structural “glue” that binds the protein into an active shape.

Initially, we only knew that vitamin K was necessary to the function of prothrombin, the precursor to thrombin, which activates fibrinogen to fibrin to form blood clots. We now know that vitamin K is also needed for properly functioning factors VII, IX, and X, which are pro-coagulant proteins involved in the conversion of prothrombin to thrombin. Vitamin K is just as necessary for the function of proteins S and C, which act as anticoagulants by inactivating other clotting factors that are not dependent on vitamin K, factors V and VIII. There is a seventh vitamin K-dependent plasma protein, protein Z, that may have additional anticoagulant functions. Thus, vitamin K is required for the proper function of both procoagulants and anticoagulants within the clotting cascade and serves as a raw material necessary for the proper regulation of blood clotting rather than serving as a coagulant or an anticoagulant itself.

The Role of Osteocalcin in Metabolic and Hormonal Health

Vitamin K is necessary for the carboxylation of osteocalcin, a protein produced in bone and also sometimes referred to as bone Gla protein. In this case, vitamin K-dependent 𝛄-carboxylation allows osteocalcin to bind to the calcified extracellular matrix of bone tissue (Koshihara, 1997).

Scientists first discovered osteocalcin in the 1970s. Since it was made in bone, most scientists in the field assumed that it played an important role in mineralizing bone or in regulating the turnover of bone mineral or the structural organization of bone. In the 1990s, however, scientists produced the osteocalcin-knockout mouse, which is genetically modified to lack the gene that codes for osteocalcin. Osteocalcin knockout mice have no obvious defects in any measures of bone health. Their bones are adequately mineralized, and although their structural architecture is slightly different than that of normal mice, one study found their bones were stronger than those of normal mice (Ducy, 1996) and the worst that could be said about their bone architecture was that it seemed “less mature” than that of normal mice (Boskey, 1998).

For three decades, the role of osteocalcin was elusive and the statements made about its function were vague and unconvincing.

In 2007, things began to change (Lee, 2007). The scientists who had developed the osteocalcin knockout mouse began more intensively investigating their phenotype and publishing papers about their metabolic and hormonal health. And here, unlike in bone, the effects of osteocalcin are dramatic.

Osteocalcin knockout mice are fat, deficient in insulin (like type 1 diabetics), insensitive to insulin (like type 2 diabetics), and they have low metabolic rates and high blood sugar.  The males are also infertile and have low testosterone (Oury, 2011).

Surprisingly, all of this is reversed with undercarboxylated osteocalcin rather than fully carboxylated osteocalcin. Undercarboxylated osteocalcin is produced by bone when vitamin K status is inadequate, and its circulation in serum had been interpreted as a sign of vitamin K inadequacy right up through the publication of these papers. In fact, some vitamin K researchers argue that it should still be used in this way, adding controversy to the implications of the osteocalcin knockout mouse studies (Booth, 2013).

I believe the best way to reconcile these conflicting ideas is as follows: vitamin K-dependent 𝛄-carboxylation of osteocalcin takes place in osteoblasts and allows the carboxylated osteocalcin (cOCN) to leave the osteoblasts and accumulate in bone matrix, which is its proper site of storage. During bone resorption, osteoclasts produce acid that decarboxylates osteocalcin and releases it into the serum in its undercarboxylated form (ucOCN) (Ferron, 2007; Oury, 2013). From there, it acts on multiple tissues to improve insulin secretion, insulin sensitivity, blood glucose, the metabolic rate, body composition, and, in males, testosterone production and fertility. This is illustrated in the figure below.

Most recently, the release of undercarboxylated osteocalcin from bone was shown to increase during exercise and play a role in allowing skeletal muscle to increase its utilization of energy (
Mera, 2016). Exercising skeletal muscle secretes interleukin-6 (IL-6), which increases the release of undercarboxylated osteocalcin (ucOCN) from bone. ucOCN stimulates muscle to release more IL-6, and they amplify one another in a positive feedback loop. IL-6 acts on liver to release glucose and adipose tissue to release free fatty acids. IL-6 and ucOCN act on skeletal muscle to increase the uptake of glucose and fatty acids and increase their utilization for energy. This is illustrated in the figure below.

Matrix Gla Protein (MGP) Regulation of Calcium Distribution

Vitamin K is necessary for the carboxylation of matrix Gla protein (MGP), which is made primarily in vascular smooth muscle cells and chondrocytes (cartilage cells) (Luo, 1997). Wherever there is a blood supply, there is MGP, so MGP is made throughout the body. In this case, vitamin K-dependent 𝛄-carboxylation allows MGP to bind calcium so that it can prevent calcium from going into the wrong places, like into the kidneys and blood vessels, and help it go into the right places, like the extracellular matrix of bones and teeth.

MGP appears to act primarily by limiting the formation of calcium salts. This helps prevent pathological calcification of soft tissues (tissues other than the bones and teeth). For example, MGP protects against kidney stones and against the calcification of blood vessels that occurs in heart disease. Bone has a complex protein infrastructure that becomes mineralized through the entry of very small calcium phosphate salts from blood. By limiting the size of these salts (Price, 2009), MGP helps them penetrate bone matrix and support its mineralization. MGP also supports growth during infancy, childhood, and adolescence by preventing premature calcification of the cartilage that helps bones to become larger.

These roles of MGP are illustrated in the figure below.

MK-4 and Gene Expression

As described below, different forms of vitamin K reach different tissues to different degrees, so some forms better support some of the health outcomes discussed above than others. However, all the roles described above can be fulfilled by any form of vitamin K able to reach the relevant tissues. By contrast, MK-4 is a subform of vitamin K2 that has a unique role in regulating gene expression (Ichikawa, 2007; Ito, 2011). The mechanisms involved are unclear: some studies show that it binds to the steroid X receptor (SXR), while others show that it regulates gene expression through SXR-independent mechanisms. One of those mechanisms is to stimulate the phosphorylation of protein kinase A (PKA), but how it does this is also unclear: some studies show that it increases cyclic AMP (cAMP), a traditional PKA activator, while other studies show it activates PKA independently from cAMP. In other words, we know that MK-4 regulates gene expression, but we have a lot to learn about how it does this.

Through its regulation of gene expression, MK-4 favors bone growth, protects against cancer, and increases the production of sex hormones.

Other Functions of Vitamin K

There are a variety of other vitamin K-dependent proteins whose functions are less clearly understood (Suttie, 2014). These include the following: Gla-rich protein, which accumulates in soft tissues during pathological calcification; periostin, which may be necessary for growth; Gas6, which promotes cell survival, and, along with protein S, helps clear away the debris of dead cells (for example, in atherosclerosis, where accumulating debris of dying cells causes a dangerous inflammatory state); and a family of four transmembrane Gla-rich proteins may act as cell surface receptors. Vitamin K also supports the production of important sulfur-based lipids known as sulfatides in the brain, and accumulates in the mitochondrion where it may play a direct role in the electron transport chain, as it has been shown to do in fruit flies (Vos, 2012).


Evidence For the Health Benefits Of Vitamin K2

We can have varying degrees of confidence in different health benefits attributed to vitamin K. In this section, I refer generally to vitamin K. I discuss the difference between vitamins K1 and Kbelow. This section is meant to be readable on its own, but if you don’t have a background in the biochemistry of vitamin K, it will be helpful to read the biochemistry section first.

Evidence for the Role of Vitamin K in Blood Clotting

The only incontrovertible effect of vitamin K is to support blood clotting (Suttie, 2014). On this basis, vitamin K is used to prevent hemorrhage in infants and inhibitors of vitamin K recycling such as warfarin and other 4-hydroxycoumarins are used as the principle anticoagulant therapy. Genetic deficiencies in vitamin K-dependent clotting factors lead to well characterized coagulation disorders, and otherwise fatal cases of bleeding can be rescued with fully carboxylated clotting factors. Thus, there is no room for a reasonable person to doubt this role of vitamin K.

Evidence for the Role of Vitamin K in Controlling Calcium Distribution

Vitamin K supports the carboxylation of matrix Gla protein (MGP), which controls the distribution of calcium in the body and thereby supports the mineralization of bones and teeth, prevents the pathological calcification of soft tissues such as the heart, blood vessels, and kidneys, and supports growth during early development by preventing the premature calcification of growth plates.

These roles are most clearly demonstrated in the MGP knockout mouse (Luo, 1997). It has short stature because of calcified growth plates, suffers from osteopenia and spontaneous fractures, and dies within two months due to the rupture of heavily calcified blood vessels. In other words, calcium fails to go into the right places (bone) and instead goes into all the wrong places (blood vessels and the growth plate cartilage). The evidence that MGP plays the same role in humans is extensive, and the sections below discuss that evidence in the context of each specific health benefit.

Evidence for the Role of Vitamin K in Heart Health

The evidence for the importance of vitamin K in heart health is compelling. Uncarboxylated MGP accumulates in atherosclerotic plaque in proportion to the amount of calcium deposited in the plaque (Roijers, 2011) and circulates in plasma in proportion to the severity of vascular calcification (Schurgers, 2010; Dalmeijer, 2013). Inhibitors of vitamin K recycling such as warfarin and other 4-hydroxycoumarins worsen blood vessel calcification in patients at risk for heart disease (Zhang, 2014). People who consume more vitamin Kin the diet have a lower risk of heart disease (Geleijnse, 2004; Gast, 2009; Buelens, 2009; Zwakenberg, 2016). Two different randomized controlled trials lasting three years support the role of vitamin K in heart health: one showed that vitamin K1 prevents the worsening of arterial calcification (Shea, 2009) and the other showed that vitamin K2 reduces arterial stiffness (Knapen, 2015). The first randomized controlled trial using vitamin K2 to prevent or reverse arterial calcification is currently underway and will likely be finished by 2018 (Vossen, 2015). Thus, a wide array of observational and experimental evidence in humans agrees that dietary vitamin K supports heart health.

Evidence for the Role of Vitamin K in Bone Health

A number of randomized controlled trials from Japan have shown that a very high pharmacological dose (45 mg/day) of vitamin K2 as MK-4 exerts powerful protection against fracture risk in women with osteoporosis (Iwamoto, 2013). However, this pharmacological dose is far higher than what anyone could obtain from food, so its effects cannot be generalized to K2-rich foods or supplements using nutritionally relevant doses.

The question is whether nutritional doses, which I would define as those under one milligram per day, offer meaningful support to bone health. Observational studies have associated the use of vitamin K antagonists as anticoagulants with lower bone mineral density (Caraballo, 1999) and have associated self-reported vitamin K intake with higher bone mineral density (Macdonald, 2008; Kim, 2015) and a lower risk of hip fracture (Apalset, 2011). Similarly, intake of natto, the richest source of vitamin K2, is associated with  less bone loss over time in postmenopasual women (Ikeda, 2006).

There are several randomized controlled trials (RCTs) using nutritional (100-200 μg/d) or borderline nutritional (1.5 mg/d) doses of vitamin K that suggest improvements in bone health, but they are not consistently convincing. Some show the improvement only in the lumbar spine (lower back) (Inoue, 2001; Moschonis, 2011; Kanellakis, 2012), and others only in the forearm (Koitaya, 2014; Bolton-Smith, 2007); one claims a benefit on the basis that bone health got worse in the control group or better in the vitamin K group without any difference between the two groups at the end of the study (Koitaya, 2014); and none of them report an improvement in whole body BMD or a decrease in the risk of fracture.

Among all of the RCTs, the most convincing one showed that three years of 180 μg/d vitamin K2 as MK-7 improved several measures of bone health in postmenopausal women when compared to a placebo (Knapen, 2013). Bone mineral density and bone mineral content both increased at the lumbar spine (lower back) and femoral neck (the “ball” that fits into the hip “socket”), although not at the hip itself. Estimates of bone strength improved, and less shrinkage occurred in the height of the thoracic spine (mid-back). Although the number of fractures was too small for statistical tests, six subjects in the placebo group but only one subject in the vitamin K group suffered vertebral fractures. This latter finding hints at a possibly very large reduction in the risk of fracture, but a larger study with sufficient numbers of fractures for statistical tests would be needed to confirm it.

The benefits to bone health in this study did not occur until the third year. Most other trials have only been one year long. Thus, while the RCTs are not in perfect agreement, the data are consistent with a powerful effect of vitamin K that takes several years to manifest. Future studies should be larger, at least three years long, and compare different doses and forms of vitamin K in different contexts to improve our understanding of how to best take advantage of this vitamin for bone health. For now, the principle is sufficiently compelling to consider it likely over time that optimizing vitamin K intake is likely to provide meaningful benefits to bone health.

Evidence for the Role of Vitamin K in Dental Health

Vitamin K is centrally important to oral health. The salivary glands contain the second highest concentration of vitamin K2 within the body (Thijssen, 1994), and both vitamin K2 (Glavind, 1948) and vitamin K-dependent proteins (Zacharski, 1979) are secreted into saliva. Dentin, the tissue underneath the enamel, produces both osteocalcin and MGP (Trueb, 2007).

Between 1945 and 1946, two studies tested the ability of menadione-laced chewing gum to protect against dental cavities in humans (Burrill, 1945; Mäkilä, 1968). Menadione is a precursor to the MK-4 form of vitamin K2, but it also has direct antibacterial effects. One study showed it was effective but the second failed to replicate the findings and the topic was largely forgotten thereafter. At the time, researchers thought any effect of menadione would be a result of its antibacterial activity. A study published in the 1950s, however, found that menadione prevented tooth decay in hamsters more effectively when injected into their abdominal cavities than when given orally (Gebauer, 1955). While it’s possible that some of the abdominally injected menadione made it into the saliva where it would have direct antibacterial activity, a more likely interpretation is that the abdominally injected menadione protected against tooth decay through its conversion to vitamin K2. This conversion is variable between and even within species, and variation in the ability of humans to make the conversion could have contributed to the conflicting findings with menadione-laced chewing gum.

While no studies have yet clearly shown dietary or supplemental vitamin K to improve dental health, this is most likely a result of the dental field largely ignoring any role for nutrition in the prevention of tooth decay beyond the role of carbohydrates in promoting bacterial acid production. The ubiquity of vitamin K and its proteins in the tissues of the mouth makes its importance clear, and what we need to move forward are clinical studies that take its role seriously.

Evidence for the Role of Vitamin K in Kidney Health

Human kidneys contain high concentrations of vitamin K2 (Thijssen, 1996) and use it to activate MGP . By the mid-1980s, we knew that a vitamin K-dependent protein isolated from patients with kidney stones, presumably MGP, was between four and twenty times less effective at preventing the growth of calcium oxalate crystals compared to the same protein isolated from healthy patients (Vermeer, 1986). Patients on renal dialysis have very high circulating levels of inactive MGP, and vitamin K2 supplementation dose-dependently improves its activation (Caluwé, 2014). Observational studies show that patients who consume more than the recommended intake of vitamin K spend less time on dialysis (Boxma, 2012) and have improved survival (Cheung, 2015).

These results suggest that patients with kidney disease have very high needs for vitamin K, but it is unclear whether vitamin K deficiency is a primary contributor to the initial development of kidney disease and so far no clinical trials have shown that vitamin K supplementation can prevent, treat, or reverse the disease. Still, it seems promising that optimizing vitamin K status could be a valuable prophylactic and seems advisable for renal patients to, with medical supervision, supplement with doses shown to improve MGP activation.

Evidence for the Role of Vitamin K in Growth

When used during pregnancy, vitamin K antagonists interfere with the growth of bone and cartilage in the fetus, especially the maxilla and nose, leading to underdevelopment of the middle third of the face (Howe, 1997). Growing children and adolescents likely have a high demand for vitamin K. In boys and girls between the ages of 10-14, fracture risk increases to such an extent that a 14-year-old boy has the same risk as a 53-year-old woman (Saggese, 2002). This is accompanied by very high levels of undercarboxylated osteocalcin, ranging from 11 to 83 percent of total osteocalcin (O’Connor, 2007; van Summeren, 2007; van Summeren, 2008). Whether improved intake of vitamin K can reverse the fracture risk or improve the rate of growth remains to be seen, but should be regarded as plausible.

Evidence for the Role of Vitamin K in Metabolic and Hormonal Health

Vitamin K plays two known roles in metabolic and hormonal health: one is to support the function of osteocalcin, an endocrine hormone produced by bone tissue, and the other is to support the production of sex hormones through the regulation of gene expression. The role of osteocalcin is most clearly supported by osteocalcin knockout mice: they are obese and have low metabolic rates, high blood sugar, poor insulin sensitivity, deficient levels of insulin and males have low testosterone and infertility (Lee, 2007; Oury, 2011). The role of gene expression is most clearly supported by cellular experiments that have characterized the related mechanisms and by a study showing that vitamin K increases the expression of the enzyme that converts cholesterol to pregnenolone in rats (Ito, 2011). Pregnenolone is the precursor to all of the steroid hormones, including all of the sex hormones, and vitamin K’s support of pregnenolone synthesis increases testosterone in male rats. To date, the targets of vitamin K’s regulation of gene expression are poorly characterized and they may impact sex hormones beyond simply increasing pregnenolone synthesis.

Direct evidence that vitamin K supports these roles in humans is limited, but there are key reasons to believe that it does. The sections below discuss the human evidence in the context of each specific health benefit.

Evidence for the Role of Vitamin K in Metabolic Health

A rare genetic defect in what appears to be the osteocalcin receptor results in fasting hyperinsulinemia and postprandial glucose intolerance, suggesting that osteocalcin plays the same role in metabolic health in humans as it does in mice (Oury, 2013). As noted below, this genetic defect also results in low testosterone.

Several randomized controlled trials have shown that 1 milligram of vitamin K1 (Rasehki, 2015 a; Rasehki, 2015 b) or 30-90 mg of vitamin K2 as MK-4 (Choi, 2011; Sakamoto, 2000) given daily for one to four weeks improves a variety of markers of glucose and insulin metabolism. From among these, the trial most relevant to nutritional doses of vitamin K (Rasheki, 2015 a; Rasheki, 2015 b)  compared 1 mg/day of K1 to a placebo over four weeks and found that it lowered glucose and insulin levels postprandially (after a glucose tolerance test) but not in the fasting state. It also increased adiponectin, supporting the mechanism outlined in animal experiments whereby osteocalcin is released from bone and acts on adipose tissue to increase adiponectin, which then acts on other tissues such as muscle and liver to increase insulin sensitivity.

As described in the section on different vitamin K forms below, while certain forms of vitamin K2 may more effectively reach bone than K1, K1 does reach bone in substantial amounts, and the dose used in the Rasehki study was high. No one has yet compared nutritional doses of K1 to other forms of vitamin K, but we could predict that the forms that reach bone most effectively, such as MK-7, could prove even more effective.  

The authors of these studies have generally argued that their results contradict the animal experiments rather than supporting them. The animal experiments show that osteocalcin has to be in its undercarboxylated state to improve metabolic and hormonal health, and these  supplementation trials have shown what has already been well established, that vitamin K increases the carboxylated form and decreases the undercarboxylated form. However, the animal experiments provide a view that is much more nuanced than “undercarboxylated good, carboxylated bad.” Vitamin K is needed to “prime” osteocalcin by allowing it to accumulate in bone matrix; bone decarboxylates it and releases it in response to specific stimuli, one of which is exercise. Vitamin K deficiency causes a continuous, slow, unregulated leak of undercarboxylated osteocalcin into the blood. Supplying vitamin K to bone allows bone to properly store the hormone and release it at the right time.

While we need to learn more about osteocalcin physiology to completely reconcile all of these findings, the evidence that both vitamin K and osteocalcin are critical to metabolic health is strong.

Evidence for the Role of Vitamin K in Sex Hormone Optimization

A rare genetic defect in what appears to be the osteocalcin receptor results in low testosterone in men, suggesting that osteocalcin plays the same role in sex hormone production in humans as it does in mice (Oury, 2013). As noted above, this genetic defect also results in poor metabolic health.

Evidence that vitamin K optimizes sex hormones in humans is limited, but a recent randomized controlled trial in women with polycystic ovarian syndrome (PCOS) provides intriguing results (Razavi, 2016). PCOS is a condition involving insulin resistance and high levels of androgens (hormones that should be high in males and low in females). Compared to a placebo, a cocktail of vitamin D (400 IU), calcium, (1000 mg), and vitamin K2 (180 μg, as MK-7) taken over the course of nine weeks cut the levels of androgens in half. This could have been a result of osteocalcin-mediated improvements in insulin sensitivity, gene expression-mediated improvements in sex hormone production, or some combination of these mechanisms. The use of a nutritional cocktail precludes a definitive conclusion about the effect of vitamin K itself or how it would act alone, but the possibility that vitamin K has such a powerful effect on sex hormone optimization is promising.

Evidence for the Role of Vitamin K in Cancer

Cell experiments suggest that the MK-4 subform of vitamin K2 protects against cancer through its regulation of gene expression (Shearer, 2014). In 2004, a randomized controlled trial provided an incredible demonstration of this effect in humans: in women with viral cirrhosis, supplementation with 45 miligrams per day of MK-4 reduced the risk of liver cancer by over 80 percent over the course of 8 years (Habu, 2004).

Other trials have looked at the ability of the same exact treatment regimen to reduce the recurrence of liver cancer in people who had already recovered from it once. A meta-analysis examined five of these trials and found that vitamin K2 reduced the recurrence of liver cancer by 29-34% at two and three years (Riaz, 2012). These results are less dramatic than those of the 2004 paper, but the trials were much shorter. Even in the 2004 paper, the effect of K2 at 2-3 years was small and only became large in years four through eight of the study. Thus, it may be that this treatment is highly protective against liver cancer when carried out over a long enough duration.

The dose of MK-4 used in these studies is hundreds of times what any of us could expect to get from food. Unfortunately, we don’t know if such a high dose was actually needed. In other words, perhaps the first 200 micrograms of that dose (the first 0.44%) got rid of 80 percent of the cancer and the rest of the dose did nothing. Alternatively, it could be that such high doses have pharmacological effects that amounts of MK-4 found in food do not have. In that case, obtaining vitamin K2 from food could be irrelevant to cancer.

Observational studies offer some limited support for the importance of K2 from foods: the EPIC-Heidelberg study found that German men who consumed more than 46 micrograms per day of K2 were almost two-thirds less likely to develop advanced prostate cancer and lung cancer as those consuming less than 26 micrograms per day (Nimptsch, 2008; Nimptsch, 2010).

Thus, data from cell experiments, observational studies, and randomized controlled trials agree that vitamin Kprotects against cancer, but differences in the doses used and the types of cancer investigated leaves many open questions to be investigated by future research.

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Why the Form of Vitamin K You Eat Is So Important

Vitamin K comes in different forms. Vitamin K1 is primarily found in plant foods and is most abundant in leafy greens. Vitamin K2 is only found in animal foods and fermented plant foods.  The term “vitamin K2 ” actually refers to a collection of more specific forms known as menaquinones that are all abbreviated “MK” with a specific number attached: for example, MK-4, MK-7, MK-10, and so on.

Does it matter whether you eat one form or another? Absolutely. There are two reasons for this, so let’s deal with them one at a time.

First, once we eat foods with vitamin K in them, our bodies handle the different forms differently. Consider these examples:

    • Vitamin K1  travels to our livers more effectively than it does to our bones or blood vessels. The liver is where we use vitamin K to make the proteins involved in blood clotting, so vitamin K1 is better at supporting blood clotting than it is at providing other health benefits.
    • MK-7 is much more effective than K1 at reaching bone. This doesn’t just make it good for bones: our bones use vitamin K to produce a hormone known as osteocalcin, which improves metabolic and hormonal health and increases exercise performance. Thus, MK-7 better supports these health benefits than K1 . The portion of MK-7 that reaches the liver, moreover, stays active in the liver much longer than K1 before being broken down; as a result, MK-7 is even better than K1 at supporting blood clotting.
    • MK-4 is taken up by our tissues very rapidly after we consume it. While it hasn’t been studied as carefully as MK-7, it may be less effective than MK-7 at reaching liver and bone but more effective at reaching most other tissues. This would make it better at protecting those tissues from calcium deposits and cancer development and supporting sex hormone production through its direct actions within our sex organs.

Overall, then, the collection of different vitamin K2 compounds better supports all the health benefits listed above than vitamin K1 because they better reach the tissues that matter.

These concepts are illustrated in the shareable infographic below.

The second reason the form of vitamin K matters is that MK-4 regulates gene expression in specific ways that no other form of vitamin K does. While we tend to think of our genes as the destiny we inherited from our parents, it’s actually how they are expressed — meaning, what our cells do with the information carried by those genes — that determines our health. MK-4 turns on some genes and turns others off. For example, in our sex organs, it turns on the genes involved in sex hormone production. In a wide variety of cells, it turns on the genes that keep cells healthy and turns off the genes that make cells become cancerous. Thus, MK-4 plays an exclusive role in cancer protection and sexual health.

This special role of MK-4 probably explains why all animals break down other forms of vitamin K and convert them to MK-4. By contrast, no animal synthesizes any other form of vitamin K. This explains why MK-4 is mostly found in animal foods, and why most unfermented animal foods contain little if any of the other forms.

As humans, we also convert other forms of vitamin K to MK-4. This raises the question, do we really need to consume MK-4 directly if we can make it ourselves? My answer is yes.

There are three reasons we shouldn’t rely on the conversion:

  • First, we don’t actually know that much about how the conversion takes place, but it seems to be inefficient and highly variable according to genetics and health status, making it unreliable.
  • Second, cholesterol-lowering statin drugs and certain osteoporosis drugs inhibit the conversion, making it even less reliable in people who are taking these drugs.
  • Third, research shows vitamin K2 is better than vitamin K1 at supporting many different aspects of our health. If we easily converted as much K1 to K2 as we needed, we wouldn’t observe these superior benefits of K2.

These concepts are illustrated in the shareable infographic below.

The difference between K1 and K2 isn’t absolute. When we eat vitamin K1 some of it will reach tissues outside the liver and we will convert some of it to MK-4. But the real question is: what’s the best vitamin for the job? Vitamin K2 is clearly much better at supporting the health benefits discussed in this resource, so the resource is dedicated specifically to getting enough K2 in its diversity of forms.

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The Many Forms of Vitamin K

The names “vitamin K1” and “vitamin K2” are artifacts of history (Suttie, 2014). The first form of vitamin K was found in alfalfa, so it was named K1. The second form was found in rotten fish, so it was named K2. As shown in the figure below, they both have the same ring structure, but different tail structures. The tail structures are known formally as side chains. Vitamin K1, now known as phylloquinone, has a mostly saturated tail. Vitamin K2, now known as menaquinone, has an unsaturated tail. Menaquinones are actually a class of compounds with varying tail lengths, designated MK-n, where “n” indicates the number of repeating units in the tail. The specific form of vitamin K2 found in rotten fish was MK-7. When later MKs were discovered, they all had unsaturated tails, so scientists classified them as subforms of vitamin K2.

The Structures of Vitamin K1(Phylloquinone) and VitamiN K2 (Menaquinone)

We now know that this is overly simplistic (Shearer, 2014). Some bacteria, such as those used to make Jarlsberg cheese, produce partially saturated menaquinones wherein some of the repeating subunits have double bonds and others don’t. For example, Jarlsberg is very rich in tetrahydromenaquinone-9, which is similar in structure to MK-9 except the second and third units of the tail are saturated. As Shearer (2014) pointed out, even phylloquinone has a double bond in the first unit of its tail and could be seen as a partially saturated form of MK-4. Thus, rather than forming two categories of K vitamins, it makes more sense to say that vitamin K comes in a wide diversity of forms that are distinguished by the length and saturation of their tails.

Side Chain Length and Saturation Determines Tissue Distribution

While the ring structure is what allows vitamin K to support the vitamin K carboxylase, the enzyme that activates vitamin K-dependent proteins, the tail structure determines how different forms of vitamin K reach different tissues in the body. This all begins with how they are incorporated into lipoproteins soon after we absorb them from food.

When we digest fat and fat-soluble nutrients, our intestines package them into lipoproteins known as chylomicrons, which take them through the lymph and into the bloodstream. This event critically distinguishes how water-soluble and fat-soluble nutrients are distributed through the body: water-soluble nutrients travel directly to the liver through the portal vein, while fat-soluble nutrients travel through the lymph in chylomicrons to bypass the liver and nourish the other tissues first.

Chylomicrons, like all other lipoproteins, have to transport fat-soluble things through the water-based environment of the blood. Therefore, they are fat-soluble on the inside and water-soluble on the outside.

While all K vitamins are fat-soluble, they are not all equally soluble in fat. Those with longer tails are more fat-soluble than those with shorter tails; for tails of equal length, saturated tails are more fat-soluble than unsaturated tails. K vitamins that are more fat-soluble are carried deeper in the core of chylomicrons, while those that are less fat-soluble are carried more toward the edges. Let’s take the three forms most commonly found in supplements as examples: K1, MK-4, and MK-7. We would expect to find MK-7 in the center of the chylomicron, MK-4 closer to the edges, and K1 in between the two (Schurgers and Vermeer, 2002).

Chylomicrons move in and out of the bloodstream rapidly, with a half-life of 15-20 minutes (César, 2006). This means that once we eat a meal, 95% of the chylomicrons that enter our blood are fully cleared in the first hour. Very few tissues actually take up the whole chylomicron. Instead, most tissues use the enzyme lipoprotein lipase (LPL) to siphon off its nutrients bit by bit. While LPL is best known for feeding the heart, skeletal muscle, and adipose tissue, it also feeds other tissues such as the lungs, kidneys, mammary glands, and brain (Kersten, 2014). LPL spreads across the capillary beds that feed our great diversity of tissues, allowing widespread access to the fat-soluble nutrients we ingest in a meal. Presumably, these tissues all have greater access to the nutrients carried closer to the edges of the chylomicrons, such as MK-4.

As these many tissues feast on the chylomicrons, the chylomicrons get smaller and smaller until they become chylomicron remnants. A small handful of tissues donate apolipoprotein E (ApoE) to the chylomicron remnants, and then use the LDL receptor and other related receptors to bind to the ApoE and take up the whole remnant. This allows them to score everything left in the particle right down to its chewy center. In this sense, ApoE is like the bait on a fishing line, and the receptor is like the hook. While the liver is best known for fishing out chylomicron remnants in this manner, our bones and spleen do as well. Our bones primarily derive nutrients through the uptake of whole lipoprotein particles, and take up about a fifth as many chylomicron remnants as our liver (Shearer, 2008). Thus, we should expect bone and liver to primarily have access to nutrients carried in the center of chylomicrons, including K1, but especially the MKs with longer tails, such as MK-7.

This whole stream of events takes place largely in the first hour after a meal. The liver then repackages the lipids it took in from chylomicron remnants into other lipoproteins, primarily VLDL, which are sent back out into the blood. Tissues continue to siphon off nutrients using LPL. Just like chylomicrons had been digested into chylomicron remnants, VLDL particles are then digested into LDL particles until our tissues take up the LDL particles themselves. Unlike the rapid clearance of chylomicrons, clearance of LDL particles takes place slowly over the course of two weeks (Langer, 1972). Although the liver is the main tissue that takes up LDL, bone is also important; in fact, bone takes up vitamin K more effectively from LDL than from any other lipoprotein (Shearer, 2012). Thus, K vitamins that get packaged into LDL particles will have a second opportunity to nourish bone.

Schurgers and Vermeer (2002) investigated how different K vitamins are transported using K1, MK-4, and MK-9. They fed six healthy males a mixture of one milligram of each form and took repeated blood measurements over four days, beginning at the two-hour mark. MK-4 had already peaked by the time the first blood draw was taken, when much of it was found in HDL, and disappeared most rapidly from the blood out of all the forms. K1 peaked at the four-hour mark, was mostly gone by eight hours, and disappeared by the end of the study. K1 was found almost exclusively in VLDL rather than in LDL or HDL. MK-9 peaked at the four-hour mark as well, but persisted in the blood for several days while carried in LDL particles.

The authors suggested that MK-4 was taken up so quickly because it was carried toward the edges of the chylomicrons, making it easily accessible for LPL-mediated extraction, with the excess spilling over into HDL particles. Notably, we should expect the extended circulation of MK-9 in LDL to provide better nourishment to bone.

Schurgers later collaborated with Sato (2012) to compare the bioavailability of MK-4 and MK-7 in healthy women. Compared to the 2002 study, they used less than half the dose of each vitamin and fed them separately rather than combined so that the total dose of vitamin K given at each point was over six times lower. Similar to the 2002 study, they took their first blood sample at two hours. They didn’t find MK-4 in the blood at any time point, whereas MK-7 remained elevated for two days.

MK-4 vs. MK-7: What Do We Really Know?

If we compare the results of the 2012 study to the earlier 2002 study, we can surmise that the dose of MK-4 in the 2012 study was low enough that the initial LPL feast in the first hour fully distributed it to a variety of tissues so that it was all gone by two hours, and that MK-7 circulated for such a long time because, like MK-9, it was redistributed in LDL particles. We should expect from this that MK-4 is good at nourishing most tissues, but not very good at nourishing liver or bone. By contrast, we should expect that MK-7 is good at nourishing the liver and even better at nourishing bone.

At the present time, there is no direct support for this, but there are hints that it may be the case. Sato (2012) cited a Japanese paper as finding that 1.5 milligrams of MK-4, but not 500 μg, improved the carboxylation of osteocalcin. Not even the abstract seems to be available in English, so it is difficult to evaluate the study. Later, Nakamura (2014) showed that only 600 μg of MK-4 is needed, but in this study the researchers simply gave the same people higher and higher doses each week and waited for osteocalcin carboxylation to improve. For all we know, their lowest dose, 300 μg, would have worked if they had given it longer than a week. In seeming contrast to MK-4, MK-7 improves osteocalcin carboxylation with as little as 100 μg (Knapen, 2012; Inaba, 2015).

Placing these studies side by side, they seem to suggest that improvements in osteocalcin carboxylation require much lower doses of MK-7 than of MK-4. However, the studies had different designs and were conducted in different populations that may have had different nutritional needs and different responses to vitamin K supplementation. In fact, Inaba (2015) fed MK-7 for four weeks while Nakamura (2014) only fed each dose of MK-4 for one week. This alone could explain the difference. To date, no one has compared the osteocalcin response to MK-4 and MK-7 head-to-head.

On the other hand, MK-7 has been compared to K1. At equal doses, MK-7 is three times more potent than K1 at carboxylating osteocalcin (Schurgers, 2007). Osteocalcin is made in bone, so its carboxylation reflects vitamin K status in that tissue. Presumably, MK-7 is better than K1 because its recirculation in LDL particles for days after it is first taken up by the liver gives it much more opportunity to nourish bone. Since MK-4 likely has even less opportunity to reach bone than K1, MK-7 is probably superior to MK-4 for this purpose as well.

What about other tissues? Unfortunately, we know even less about those. We know that large pharmacological doses of MK-4 given to rats (Konishi, 1973) or dogs (Sano, 1997) reach the lungs, liver, kidney, pancreas, spleen, adrenal gland, and bone very rapidly. Such large doses are also excreted into the feces in large amounts. More moderate nutritional doses could behave very differently, however, so it is difficult to form any conclusions from these studies. Until we have well designed trials comparing the ability of different MKs to support different health outcomes in humans, it makes sense to rely on what we know generally about how lipoproteins transport nutrients. This suggests K1 would best reach the liver, MKs 7-9 would best reach liver and bone, and MK-4 would best reach most other tissues.

MK-7 Supports Blood Clotting Better Than K1

MK-7 is not just three times better than K1 at reaching bone; it’s also five times better at supporting blood clotting (Schurgers, 2007). This may be because the greater fat-solubility of MK-7 makes it hold on more tightly to the membranes within liver cells, making it stay active in the liver much longer rather than being released and broken down (Shearer, 2008). The liver is where clotting proteins are made, so more extended activity in the liver would explain why MK-7 could better support blood clotting. If this is correct, other long-chain MKs such as MK-8 and MK-9 probably share this property as well.

MK-4 Plays a Unique Role in Gene Expression

MK-4 is unique among the K vitamins in its regulation of gene expression. It increases the expression of genes that regulate cell growth in osteoblasts (the cells responsible for bone growth), but MK-7 and K1 do not (Ichikawa, 2007). MK-4 increases testosterone production when fed to male rats. Cellular experiments show that MK-4, but not K1, increases testosterone  by increasing the expression of the enzyme that converts cholesterol to pregnenolone, which is the first step in sex hormone synthesis (Ito, 2011).

MK-4 also inhibits the growth of various cancers of the liver, gut, and bone (Shearer, 2008). Remarkably, the gene that is now known to code for the enzyme that converts other K vitamins to MK-4, Ubiad1, was known years earlier as a tumor-suppressor gene (Shearer, 2014). Scientists observed that Ubiad1 was often silenced in tumors of the bladder, prostate, and kidney. Conversely, experimental overexpression of Ubiad1 inhibited the growth of prostate cancer cells. Since the enzyme that Ubiad1 codes for converts other K vitamins to MK-4, these results underscore that the anticancer properties of vitamin K belong specifically to MK-4.

Can We Rely on the Conversion of Other K Vitamins to MK-4?

When we consume any form of vitamin K, our intestinal cells break the side chains off of a small portion to yield the pure ring structure, known as menadione (Thijssen, 2006). Menadione then disperses through the body to many tissues that convert it to MK-4 for their own use by adding  MK-4’s characteristic four-unit unsaturated side chain (Hirota, 2013).

We have known that animals synthesize MK-4 from other K vitamins for over a half century. It has been clear throughout that time, however, that the conversion varies widely. Early experiments, for example, showed that birds made the conversion better than rats and pigeons made it better than other birds (Billeter, 1960). Among rats, Wistar rats (Thijssen, 1994) seem to make the conversion better than Lewis rats (Ronden, 1998). Since the conversion varies between and within species, we should not assume that we as humans can make the conversion efficiently and consistently enough to meet our needs.

And just how good are we at this conversion? We really don’t know, but it stands to reason that it varies from person to person. Rare genetic defects in Ubiad1 have been identified (Yellore, 2007), and cancer is associated with epigenetic silencing of Ubiad1 (Woolston, 2015). Other genes involved in the conversion likely vary from person to person as well, but we don’t yet know what they are. One of them may be vitamin K epoxide oxidoreductase (VKOR), the target of warfarin. The normal role of VKOR is to reduce vitamin K that has been oxidized, and we know that menadione must be in a reduced state to undergo conversion to MK-4. Indeed, warfarin prevents the conversion of K1 to MK-4 in rats (Spronk, 2003). Genetic polymorphisms in VKOR are common (Shearer, 2012), and could hypothetically contribute to variation in MK-4 synthesis. We still do not know what enzyme is responsible for cleaving the side chain within our intestinal cells, and that could be polymorphic as well.

However good or bad humans may naturally be at the conversion, many people are taking medications that inhibit it (Hirota, 2015). Lipophilic statins such as lovastatin and simvastatin (and presumably atorvastatin, branded as Lipitor) inhibit the conversion. So do nitrogen-containing bisphosphonates such as alendronate (Fosamax) and zolendronate (Zometa), and presumably other nitrogenous bisphosphates as well. Ubiad1 expression depends on zinc (Funahashi, 2015) and its enzymatic activity depends on magnesium (Hirota, 2015), suggesting that deficiencies of either of these minerals could also compromise the conversion.

Finally, if we converted other K vitamins to MK-4 on a “however much we need to” basis, then it shouldn’t matter what type of vitamin K we consume at all. All forms of vitamin K generate some menadione in the intestine that can be converted to MK-4 in other tissues. Whether the menadione comes from K1, MK-4, MK-7, or any other form of vitamin K cannot make any difference in its tissue distribution. Humans accumulate MK-4 in multiple organs including the heart, lung, brain, liver, kidney, and pancreas (Thijssen, 1996). Thus, if there are no major limitations on the conversion besides our need for it, K1 should be perfectly capable of supplying these tissues with all the MK-4 they need, especially in populations that have high K1 intakes. Yet this does not seem to be what we find.

Consider the Dutch population, where this has been investigated most extensively. K1 intakes are eight times higher than K2 intakes, yet only K2 intake is inversely correlated with heart disease (Geleijnse, 2004; Gast, 2009; Buelens, 2009; Zwakenberg, 2016). In Germany, K1 intakes are about three times higher than K2 intakes, yet only K2 intake is inversely correlated with advanced prostate cancer (Nimptsch, 2008) and lung cancer (Nimptsch, 2010).

These observational studies don’t offer clear evidence of cause-and-effect relationships and they don’t show correlations with health endpoints that are specific to MK-4. However, they do add to the list of reasons to believe that our ability to synthesize MK-4 is limited by much more than our specific need for MK-4 itself, and by much more than our general need for vitamin K in the tissues that unconverted K1 has a hard time reaching. In other words, many of us probably need more MK-4 than we can make on our own, and that’s a good reason to eat foods that provide it.

Altogether, the evidence suggests that the form of vitamin K we consume matters, and that we are best served by a diversity of K vitamins from leafy greens, animal foods, and fermented foods.

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How Much Vitamin K2 Do We Need?

Currently, there are no official recommendations about vitamin K2. In the United States, the current recommendation for total vitamin K is 90 μg per day for adults. In a typical diet, most of this would come from K2. These recommendations were last updated in 2001, before we learned about most of the benefits of K2. In fact, the USDA did not even develop a database of vitamin K2 in foods until 2006. My recommendation, therefore, does not rely on official sources and is meant for health-conscious people who wish to take advantage of cutting-edge research.

Based on the current state of that research, I recommend 100-200 μg per day of vitamin K2 for healthy adults. Although most of the benefit probably comes from the first 100 μg, 200 μg is harmless and may provide additional benefit. If your health is fantastic while maintaining a K2intake close to 100 μg, I would not worry about increasing your intake. But if you could stand to gain from the wide array of health benefits provided by the vitamin, I would use food or supplements to bring your intake closer to 200 μg.

Patients with chronic kidney disease may require doses as high as 480 μg per day and possibly much higher, but the use of high doses to treat a disease should always be done under medical supervision.

Patients using warfarin (Coumadin) or any other anticoagulant medications related to it should not make any changes to their vitamin K intake, regardless of the specific form of vitamin K, whether from food or supplements, except under the strict supervision of the prescribing physician (see below).

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Vitamin K2: What is the Optimal Dose?

Another way to ask this question is as follows: what is the minimum effective dose to achieve the maximal desired effect? While there is no established toxicity for high doses, there are good reasons to be cautious before taking far more than we need (see below), hence the term “minimum effective dose.” At the same time, we don’t want to reap just some of the health benefit. We want to reap as much of the health benefit as we can in a safe and effective manner, hence the term “maximal desired effect.”

The only rigorous way to approach this is to look at dose-finding studies, which are studies where different doses were directly compared with one another. Ideally, the studies are randomized, controlled, long enough in duration to believe the dose was able to achieve its full effect, and conducted within a context where we would expect to see a benefit.

Pharmacological Doses of MK-4

A Japanese dose-finding study compared 15, 45, 90, and 135 milligrams per day (mg/d) of MK-4 to reduce fracture risk in postmenopausal women with osteoporosis and found 45 mg/d to be the minimal effective dose (Iwamoto, 2013). This is a pharmacological dose that is hundreds of times greater than what can be obtained from food. It probably works through mechanisms that are independent of the those seen for nutritional doses of vitamin K, such as overriding the body’s natural regulation of bone resorption. Thus, we should view MK-4 at these doses with the same type of cost-benefit analysis we would use for other osteoporosis drugs, like Fosamax, and we should not use these studies to determine the optimal nutritional dose of MK-4.

Nutritional Doses of MK-4

Unfortunately, there is a dearth of dose-response studies for nutritional doses of MK-4. Nakamura (2014) compared the effect of 0, 300, 600, 900, and 1500 micrograms per day (μg/d) on osteocalcin carboxylation, a marker of vitamin K status in bone. They fed everyone the same doses in the same order, increasing the dose from 0 one week at a time. The carboxylation status did not change with 300 μg/d, but improved with 600 μg/d. However, it is not at all clear that 300 μg/d would not have provided the same benefit if given for longer than one week. I do not consider this study to offer any clear insight about the optimal dose of MK-4.

MK-7 in Healthy Populations

Dalmeijer (2012) compared 180 and 360 μg/d MK-7 to a placebo given to healthy, non-obese men and postmenopausal women aged 40-65 years over the course of twelve weeks. The mean K2 intake from food was 25 μg/d, so these treatments effectively compared total K2 intakes of 25, 200, and 380 μg/d. Both treatment doses lowered desphospho-uncarboxylated MGP (dp-ucMGP), a marker of vitamin K deficiency in blood vessels, and improved the carboxylation status of osteocalcin. While 360 μg seemed to cause a slightly larger effect than 180 μg, the lion’s share of benefit came from 180 μg and the difference between the two doses was not statistically significant. Thus, the study hints at a possible benefit of doses higher than 200 μg that would have to be confirmed in future studies with greater statistical power, but provides rigorous evidence only that 200 μg is better than 25 μg.

Knapen (2012) reported a more extensive array of doses given to healthy men and premenopausal women aged 25-45 over the course of twelve weeks. The doses included 0, 10, 20, 45, 90, 180, and 360 μg/d MK-7 and the primary endpoint of interest reported was the carboxylation status of osteocalcin. Unfortunately, the sample size (n=42) was small for having so many groups, precluding a rigorous statistical analysis of the endpoints between each group. Additionally, while carboxylated osteocalcin levels were similar across groups at baseline, undercarboxylated osteocalcin levels were highly variable. The changes in undercarboxylated osteocalcin between baseline and the study’s end within any given group were generally about the same size as the difference in baseline values between groups. All of this makes it extremely difficult to know whether the the difference between groups for changes in undercarboxylated osteocalcin or its ratio to total osteocalcin are true biological differences or simply random variation resulting from noisy data.

Doses that were 90 μg/d or greater caused statistically significant decreases in undercarboxylated osteocalcin, but only the 180 μg and 360 μg doses increased the levels of carboxylated osteocalcin or improved the ratio. From among these measurements, the increase in carboxylated osteocalcin seen with the two higher doses is most convincing because the variation in baseline values for that measurement was so low. The ending values for this measurement were higher in the 180 and 360 μg groups than in any of the the others, but they were nearly identical between groups. K2 intake from food was not reported, but presumably would have added at least 20 μg/d to the doses. I therefore consider this study to offer limited support to 200 μg/d as the optimum dose for improving vitamin K status at bone.

Inaba (2015) compared 0, 50, 100, and 200μg/d MK-7 in postmenopausal women aged 50 to 69 years over the course of four weeks. The primary endpoint of interest was the carboxylation status of osteocalcin, reported as the ratio of the carboxylated to the undercarboxylated form. The study was conducted in Hokkaido, Japan, where natto is popular. The subjects were required to avoid all MK-7-rich foods and to consume prepared meals that provided 65 μg/d of total vitamin K as a combination of K1 and MK-4 in unspecified proportions. Whether intentional or not, this is effectively a study of how much MK-7 you need to preserve the carboxylation status of your osteocalcin when you stop eating natto. Indeed, the largest effect across all groups was for carboxylation status to significantly worsen in the 0 μg/d group. Carboxylation status was significantly different from that group in the 100 and 200 μg/d groups, but not in the 50 μg/d group. The authors did not report a statistical analysis for the difference between 100 and 200 μgd, but 200 μg/d was the only group in which carboxylation status actually improved over the course of the study. I therefore consider this study to offer limited support to 200 μg/d as the optimum dose for improving vitamin K status at bone.

In further support of this conclusion, Ikeda (2006) found that postmenopasual women who reported consuming enough natto to provide 200 μg/d K2 or more (mostly as mostly MK-7) suffered less bone loss over the course of three years than women who consumed less. Since all lower intakes of natto were grouped together for the statistical analysis, it is not clear exactly where the line of maximal benefit lies, and it may be less than 200 μg/d. As an observational study, we should also be more cautious about inferring cause and effect. Nevertheless, the fact that it measured an actual health endpoint (bone loss) instead of just a surrogate marker (osteocalcin carboxylation), and the fact that it was three years long instead of four to twelve weeks, makes it very worthy of consideration.

MK-7 in Hemodialysis Patients

Westenfeld (2012) and Caluwé (2014) both conducted dose-finding studies in hemodialysis patients. Patients with kidney disease have high levels of vascular calcification, which is a major contributor to mortality in this population. Since MGP protects blood vessels from calcification, dp-ucMGP was the major endpoint in both studies. Lower dp-ucMGP suggests better vitamin K status in blood vessels and a better defense against pathological calcification.

Westenfeld compared 45, 135, and 360 μg/d MK-7 over six weeks. MK-7 dose-dependently decreased dc-ucMGP, with the effect almost doubling in size for each increase in the dose from 18% to 37% to 61%. However, change from baseline analysis is vulnerable to regression to the mean and it is more rigorous to compare the absolute levels of dc-ucMGP after treatment. When looked at this way, 135 and 360 μg/d had equal benefit over 45 μg/d.

Nevertheless, Caluwé later tested even higher doses and provided evidence of benefit for more than 300 μg/d. They fed the patients 360, 720, or 1080 μg MK-7 three times per week for eight weeks, which equates to average daily doses of 154, 309, and 463 μg. MK-7 dose-dependently decreased dp-ucMGP by 17%, 33%, and 46%. The ending dp-ucMGP values were lower in the 463 μg/d group than in the 309 μg/d group and were lower than Westenfeld found after feeding 360 μg/d, but they were still about four times higher than that found in healthy controls. The average K2 intakes in the Caluwé paper were 16 μg/d, making the doses compared effectively 325 and and 479 μg/d. Future studies may clarify whether even higher doses can bring dp-ucMGP levels even closer to those found in healthy controls. Thus, there is strong evidence that the K2 requirement for kidney patients is higher than 325 μg, possibly as high as 480 μg, and may well be much higher than that.


For healthy populations, there is no smoking gun, but several studies converge towards the conclusion that 200 μg/d is the optimal dose. Most of the benefit probably comes from the first 100 μg, and the evidence for the superiority of 200 μg is limited. There may be benefits to higher doses, but there is no convincing evidence of that at this time. Thus, there is a high likelihood that I will revise my recommendation as new data comes in, but I currently recommend at least 100 μg/d and preferably 200 μg/d.

For kidney disease patients, there is good reason to see 480 μg/d as better than lower doses. Since 480 μg/d almost slashes dp-ucMGP in half yet leaves it four times higher than in healthy controls, the optimal dose may well be much higher than this. I suspect it is at least 1 mg/d. Nevertheless, K2 should only be used to augment treatment for kidney disease under medical supervision.

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How to Get Enough Vitamin K2 From Food

You can use the searchable database we created to determine how much vitamin K2 is in your diet. In this section, I describe a few of the simplest ways to get 200 μg per day of K2 from foods. As noted above, most of the benefit comes from the first 100 μg, so any of the values below can be cut in half to obtain that amount.

The foods that are richest in K2 are natto and goose liver, both of which may be difficult-to-acquire tastes. Natto is a fermented soy food popular in eastern Japan. The source of K2 is the bacteria used in the fermentation, not the soy beans. As a result, any vegetable fermented with natto bacteria should be rich in K2. For example, 100 grams of traditional natto contains just under 950 μg, while 100 grams of natto made from black beans contains almost 800 μg. The value for black bean natto is a little lower than that for traditional natto, but both values are phenomenally high. Simply adding 18 grams of natto (about two-thirds of an ounce) to your diet each day would give you 200 μg, and just two ounces of goose liver would provide the same benefit.

Another excellent source of vitamin K2 is cheese. The K2 content of cheese varies widely according to the type of bacteria used to make it. To browse a full list of cheeses, search “cheese” in our database or leave the search box blank and select the category “Dairy Foods and Eggs.”

Jarlsberg cheese, which originates from Norway, is richest in K2. According to the value listed in our database, it would take nine ounces of Jarlsberg to provide 200 μg. Its true content of K2 has likely been underestimated, however, and it may actually take as little as 4.5 ounces.

Egg yolks and the dark meat (legs and thighs) of chicken are also good sources. For example, four whole eggs provides over 20 μg and 100 grams of dark chicken meat provides 60 μg.

Ultimately, it is the way these foods are combined in your diet that determines how much K2 you get. The first infographic provides some ideas of how to work these different foods into a meal to make a meaningful contribution to your daily K2 intake. You can figure out how much K2 other meals would provide by using our database.

Surprisingly, we recently learned that pork products are very high in MK-10 and MK-11. This is a newly discovered exception to the rule that fresh animal products mostly contain MK-4. Unfortunately, little is known about the bioavailability of these forms and there are some indications that we as humans largely store them in our livers rather than distributing them throughout our bodies like other forms of K2. However, if future research were to show that MK-10 and MK-11 have similar benefits as the other forms, that would mean most pork products are competitive sources. For example, only 4.5 ounces of baby back pork ribs would be needed to provide 200 μg, and just two ounces of pork sausage would provide the same amount.

Food quality is important. Egg yolk from The Netherlands is reported to have twice as much K2 as egg yolk from the United States. The reasons for this are unclear, but it may relate to the ways the chickens were raised. Wherever possible, I recommend using meat, eggs, and dairy from animals raised on pasture. For egg yolks, look for the most deeply colored yolks you can find.

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Vitamin K2 in Foods: A Closer Look

Vitamin K2 in foods comes either from the conversion of other K vitamins to MK-4 in animals or from bacterial production of various MKs. A good example that ties these concepts together is cheese. A cow eats grass that contains K1. The cow converts a portion of that K1 to MK-4. Both K1 and MK-4 are found in the milk. Humans take the milk and ferment it into cheese. During the fermentation process, bacteria proliferate that synthesize a variety of MKs, mainly MK-7 through MK-10, and especially MK-8 and MK-9.

A comparison of different cheeses illustrates the importance of the specific type of bacteria used in the fermentation. For example, in each 100 gram serving, Jarlsberg contains 74 μg while blue cheese contains 36, cheddar contains 21, Swiss contains 8, and mozzarella only contains 4. This variation can also be seen among fermented plant foods. For example, sauerkraut has only 5 μg, compared to nearly 1000 for natto.

Within a particular type of cheese, ripening has little effect. For example, gamalost increases from 38 to 51 in the first ten days of ripening, but this level remains mostly stable over the course of 20, 30, and 60 days. This is probably because the bacteria that produced the K2 during the initial stage of fermentation die off during the ripening (Hojo, 2007).

The data for cheese also provide a window into the possibility that some of our current food data are gross underestimates. For example, most cheeses are made with lactic acid bacteria that produce mostly MK-8 and MK-9, but some cheeses are made with proprionibacteria that also produce tetrahydro-MK-9 (Hojo, 2007), which has a structure that is the same as MK-9 except it lacks some double bonds in its side chain. These include the Swiss cheeses Emmental and Gruyère, the French cheese Comté, and the Norwegian cheese Jarlsberg. Whether tetrahydro-MKs might be present in other foods is somewhat unclear because virtually all analyses of vitamin K in foods have ignored them. No analysis has yet evaluated both tetrahydro-MKs and all the regular MKs in any food at the same time, strongly suggesting that the total K2 in foods that contain tetrahydro-MKs is grossly underestimated. To take Jarlsberg as an example, Hojo (2007) showed that, per 100 grams, it contains 8 μg MK-4 and 65 μg tetrahydro-MK-9, and cited evidence that it also contains another ~50 μg of MK-8 and MK-9. In our database, we only report values that were measured in a single scientific paper for any given sample, so our data for Jarlsberg reflects what was actually measured in the Hojo paper, 74 μg, but the true value may be over 130 μg.

Our own gut microbiota also synthesize K2: Bacterioides synthesize MK-10 and MK-11, Enterobacteria synthesize MK-8, Veillonella synthesize MK-7, and Eubacterium lentum synthesizes MK-6 (Shearer, 2014). However, this probably makes little if any contribution to our own vitamin K status for two reasons: first, most of this occurs in the large intestine, which is well past the sites of vitamin K absorption in the small intestine, and all the K2 is stuck in bacterial membranes that would have to be digested to release it.

MKs produced during the fermentation of foods such as cheese or natto are also bound in bacterial membranes, but when we eat them we digest those membranes to release the K2 in the small intestine where it can be absorbed. Some animals eat their own feces, a practice known as coprophagia, and this allows the the microbiota-derived K2 to be released and absorbed in the same way as when we eat cheese or natto. This may explain the recent finding that pork products are extremely rich in MK-10 and MK-11 (Fu, 2016). The meat was obtained from supermarkets in Eastern Massachusetts, so it presumably came from commercial farms. Perhaps pigs on those farms whether by instinct, necessity, or accident, consume feces.The only other possibility would seem to be that the pigs are fed rotten or fermented food.

The question arises whether MK-10 and MK-11 provide similar bioavailability to the MKs in other foods, which are generally much richer in MK-4 (animal foods), MK-7 (natto) or MK-8 and MK-9 (cheese) than in MK-10 or MK-11. In humans, MK-10 and MK-11 tend to predominate in the liver rather than in other tissues, and in the mitochondria rather than in the endoplasmic reticulum where vitamin K-dependent carboxylation takes place (Thijssen, 1996). Thus, we should be cautious before making a conclusion about how interchangeable the MKs in pork products are with the MKs in most other foods. Ultimately this can be resolved with studies comparing the abilities of the different MKs to support different biological functions of vitamin K.

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The Three Best Vitamin K2 Supplements

Supplements should never be used to replace a good diet. A well-rounded nutrient-dense diet not only provides vitamin K itself in a greater diversity of forms than can be found in any supplement, but it also provides a full spectrum of other nutrients that work together with vitamin K to produce good health. As such, a good diet provides the context needed for a supplement to be both safe and effective.

When evaluating K2 supplements, I look for the following things:

  • Dose: I prefer a dose from which it is easy to obtain approximately 200 ug. While it is probably effective to take a larger dose less than once a day (for example, taking 1 mg every five days), it is easier to maintain the habit of taking a daily dose.
  • Form: Since different forms of vitamin K2 are distributed differently in the body, it is best to obtain a diversity of forms. In supplements, the best diversity we can obtain is to combine MK-4 and MK-7. The only supplemental MK-4 available is synthetic, but it is bioidentical, meaning it has the same chemical structure as the natural form. MK-7 on the market can be natural or synthetic; some synthetic MK-7 is bioidentical and some is not. Out of caution, I would only choose bioidentical options. Those who wish to have an entirely natural supplement should opt for MK-7 derived from the fermentation of soybeans or chickpeas.
  • Cost and convenience: For any two products that are substantially equivalent, I prefer lower cost, easy online ordering, quick delivery, and the opportunity for free shipping.

Here are my top three recommendations:

  • Innovix Labs Full Spectrum Vitamin K2— This supplement wins on its diversity of forms (without going overboard on its total dose). It contains both MK-4 (500 μg) and MK-7 (100 μg). The MK-7 appears to be synthetic but bioidentical. It costs $21.97 on Amazon, is fulfilled by Amazon, and is eligible for Prime. Taken once a day, it costs 24 cents per day. Taken once every three days to achieve an average dose of 200 μg, it costs 9 cents per day.
  • Thorne Research MK-4 — This supplement wins on cost. Its cost is nearly identical between Amazon and Iherb ($64.62 and $64.65), and if ordered on Amazon it is fulfilled by Amazon and eligible for Prime. It contains one milligram of MK-4 per drop. While the label recommends a daily dose of 45 drops, this is based on studies using pharmacological doses to treat osteoporosis. It is easy to instead take one drop per day to obtain a nutritional dose. Taken like that, it costs 5 cents per day. Taken once every five days to achieve an average dose of 200 μg, it costs one cent per day. They also make a combination of vitamin D and K2 that is more expensive but easier to get a consistent daily dose of 200 μg from. This is described in more detail in the comprehensive review below.
  • Nested Naturals K2 — This is free of GMOs, soy, and other common allergens. It is made from fermented chickpeas. The MK-7 is made by another company, MenaQ7, whose MK-7 is sold under many different names and has also been used successfully in scientific research. This is the least expensive of all of the natural MK-7 products. It contains 100 μg of MK-7 and costs 12 cents per capsule. Taken twice per day to achieve 200 μg, it costs 24 cents per day.

An interesting runner-up is Nature’s Plus, which is an affordable MK-7 supplement that is interesting mostly for its long list of features, like its background blend of plant, mushroom, and algae extracts, and its substantial list of third party certifications. It is described in more detail in the comprehensive review below.

If you have the time for home fermentation, Dr. Mercola created a starter culture that is designed to generate K2 during the fermentation of vegetables. While I do not believe this will provide a standardized amount of K2 like a commercial supplement will, I would expect it to substantially augment the K2 content of your diet.

These are my top recommendations from a much more extensive review of over twenty supplements. If you want more details, click below for the comprehensive review.

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Vitamin K2 Supplements: Quality, Convenience, and Price

Here is my comprehensive review of vitamin K2 supplements. It doesn’t cover every single supplement on the market, but it covers the supplements that provide singular doses of about one milligram or less and are easily accessible through the major online retailers Amazon and iHerb. If you would like me to review a supplement that didn’t make the list, please let me know in the comments.

I have broken the list into five categories according to whether they provide a combination of MK-4 and MK-7, only MK-4, only synthetic MK-7, only natural MK-7 from chickpeas, or only natural MK-7 from natto. Within each category, I have listed them from least expensive to most expensive.

One concern for synthetic MK-7 supplements is whether they are bioidentical. Natural MK-7 is all-trans (Bentley, 1982). If synthetic MK-7 is not guaranteed to be bioidentical, it may contain cis forms. While it is difficult to find reliable information on the biological activity of cis MK-7, cis phylloquinone fails to support vitamin K-dependent carboxylation in the rat (Knauer, 1975). Therefore, I recommend avoiding synthetic MK-7 supplements that do not guarantee the all-trans configuration. Notably, many of the MK-7 supplements use one of two products made by MenaQ7, either synthetic or from fermented chickpeas, both guaranteed to be all-trans. This MK-7 has the advantage of having been used in scientific studies and shown to be effective.

The prices listed were retrieved between December 4 and December 7, 2016 and are subject to change. Where I link to more than one way of obtaining a supplement, the cents per capsule and cents per 200 μg calculations are based on the least expensive option. Additions were made to this review on December 29, 2016. They are catalogued here.

Mixed MK-4 and MK-7 Supplements

Life Extension Super K With Advanced K2 Complex — 1 mg K1, 1 mg MK-4, 200 μg mK-7, with an additional 10 mg ascorbic acid from 25 mg ascorbyl palmitate. Sold by iHerb ($22.50) but cheaper at Amazon ($17.93). Eligible for Prime and Amazon Fresh. 20 cents per capsule, 3 cents per day to average 200 μg/d. Beware of the subscription button when buying on Amazon. The vitamins are synthetic. According to Life Extension, the MK-7 is synthesized in China and is bioidentical, but they could not verify for me that it is 100% all-trans, which is the natural form. The reason I do not advocate this supplement is because the high dose of K1 adds little value, and although there is no well characterized risk of high doses, it is possible that multiple milligrams per day of vitamin K (this supplement itself provides 2.2 mg per capsule) may unnecessarily tax the body’s antioxidant system.

Maxx Labs Vitamin K2 Complex — 500 μg MK-4, 100 μg MK-7, 100 mg calcium from calcium citrate. 20 cents per capsule, 7 cents per day to average 200 μg/d. $17.98 on Amazon, where it is fulfilled by Amazon and eligible for Prime. Be careful to avoid the subscription setting if you only want to order one bottle. Free of GMOs and allergens.

Innovix Full-Spectrum K2 — 500 μg MK-4, 100 μg MK-7. 24 cents per capsule, 8 cents per day to average 200 μg/d. $21.97 on Amazon, fulfilled by Amazon and eligible for Prime. Both forms of K2 in this product appear to be synthetic but bioidentical. It contains caramel coloring derived from non-GMO corn, a potential source of allergens. I consider this the best choice for a mixed MK-4/MK-7 supplement.

Country Life Vegan KStrawberry Smooth Melt — 500 μg total K2. MK-4 and MK-7 in unidentified proportions. 19 cents per smooth melt, 8 cents per day to average 200 μg/d. Almost identical prices on Amazon ($16.65) and iHerb ($16.67). On Amazon, it is fulfilled by Amazon and eligible for Prime. It is not clear where the vitamins come from or whether the MK-7 is bioidentical. It is free of GMOs, soy, and other common allergens.

Pure Encapsulations Synergy K — 1,000 IU Vitamin D3, 1 mg MK-4, 500 μg K1, 45 μg MK-7. 47 cents per capsule, 9 cents per day to average 200 μg/d. $56 on Amazon, where it is fulfilled by Amazon and eligible for Prime. Free of GMOs and allergens. Taken to yield an average close to 200 μg K2, the amounts of vitamin D (200 IU) and MK-7 (9 μg) are rather low compared to the Innovix Full-Spectrum K2 (20 μg MK-7) or the Thorne Research D/K2 (1,000 IU vitamin D), but the unique combination of the three vitamins may be optimal for some people whose nutritional needs fit it just right.

MK-4 Supplements

Thorne Research Vitamin K2 — 1 mg MK-4. 5 cents per drop, 1 cent per day to average 200 μg/d. Similarly priced at Amazon ($64.62) and iHerb ($64.65), and if ordered on Amazon it is fulfilled by Amazon and eligible for Prime. It is dissolved in a base of nothing but MCT oil and mixed tocopherolsd. This is the least expensive option in the list.

Thorne Research D/K21000 IU vitamin D and 200 μg MK-4. 4 cents per day to obtain 200 μg from each two-drop serving. Although available on Amazon from third party shippers at prices ranging from $36-$70, it is not eligible for Prime and it is much less expensive ($23.70) through iHerb. This is a great option for someone who also needs to improve their vitamin D status. When compared to the Thorne Vitamin K2, it has the added benefit that the dose of MK-4 is smaller so it is easier to take a consistent dose of 200 μg every day. However, don’t be fooled by the price difference: the bottle costs less (hardly more than a third the price), but on a per 200 μg basis it is four times as expensive.

Superior Source Sublingual MK-4 Tablets500 μg MK-4. 29 cents per tablet and 12 cents per day to average 200 μg per day. Similar price from Amazon ($17.59), where it is shipped and sold by Amazon as well as eligible for Prime, and iHerb ($17.79). The company claims that the sublingual formulation offers superior absorption but I’m not aware of any specific evidence of this. It contains lactose, so should be avoided by people with lactose intolerance.

Synthetic MK-7 Supplements

Amazing Nutrition MenaQ7 — 100 μg MK-7. 12 cents per capsule, 25 cents per day for 200 μg . $14.99 on Amazon where it is fulfilled by Amazon and eligible for Prime free one-day shipping. Free of common allergens and bioidentical.

Young Life Research MenaQ7 and Organic Coconut Oil — 100 μg MK-7. 16 cents per capsule, 32 cents per day for 200 μg . $19.47 from Amazon, fulfilled by Amazon and eligible for Prime. Free of common allergens and bioidentical. Non-GMO. I consider this the best balance of quality and price from among the synthetic MK-7 supplements.

Superior Source Sublingual Vitamin K2-MK7 — 100 μg MK-7. 25 cents per tablet, 50 cents per day for 200 μg . Less expensive from Amazon ($14.99) than from iHerb ($16.06). On Amazon, it is sold by Amazon and eligible for Prime,. The company claims that the sublingual formulation offers superior absorption but I’m not aware of any specific evidence of this. It contains lactose, so should be avoided by people with lactose intolerance. The company does not claim this is bioidentical.

Life Extension Low-Dose Vitamin K2 (MK-7) — 45 μg MK-7. 14 cents per capsule, 56 cents per day for 180 μg and 69 cents per day for 225 μg . Less expensive from Amazon ($12.49) than from iHerb ($13.50). On Amazon, it is eligible for Prime free one-day shipping and Amazon Fresh. According to Life Extension, the MK-7 is manufactured in Poland, but any further information is proprietary. Presumably it is synthetic and not bioidentical.

K-Force — 5,000 IU vitamin D3, 180 μg MK-7. $1.13 per capsule, and $1.13 per day to yield 180 μg or $1.20 per day to yield an average of 200 μg/d. $67.95 on Amazon, where it can be obtained with free shipping but is not fulfilled by Amazon or eligible for Prime. The company lists the MK-7 as soy-free but does not clarify its origin. Presumably it is synthetic, but it may be derived from fermented chickpeas. This supplement is useful specifically to people who need to take 5,000 IU of vitamin D per day.

Natural MK-7 From Chickpeas

These all derive their MK-7 from MenaQ7.  Everything in this section is the fermented chickpea product.

Nested Naturals K2 — 100 μg MK-7. 12 cents per capsule, 24 cents per day to take 200 μg. $21.95 on Amazon, where it is fulfilled by Amazon and eligible for free one-day shipping, but beware of the subscription button. Free of GMOs, soy, and other common allergens. This is the least expensive of the products derived from fermented chickpeas and remains the least expensive even when including those derived from natto.

Doctor’s Best Natural Vitamin K2 — 100 μg MK-7. 18 cents per capsule, 37 cents per day to take 200 μg . Almost identical prices on Amazon ($11.06) and iHerb ($11.25). On Amazon, it is sold by Amazon and eligible for Prime free one-day shipping and Amazon Fresh delivery, but beware of the subscription button. Free of GMOs, soy, and other common allergens. They also sell a 45 μg dose, but it is much more expensive if trying to achieve 200 μg per day.

Sports Research Vitamin K2 — 100 μg MK-7. 25 cents per capsule, 50 cents per day to take 200 μg . $14.95 on Amazon, where it is fulfilled by Amazon and eligible for free one-day shipping. The fermented chickpea product comes from MenaQ7, which distributes their MK-7 products under many names. Free of GMOs, soy, and other common allergens. It’s main special feature out of the fermented chickpea products is the snap-top that the company says maintains better freshness.

Dr. Mercola Vitamin K2 — 150 μg MK-7. 79 cents per capsule: 79 cents per day to take 150 μg , $1.58 per day to take 300 μg , or $1.05 per day to take an average of 200μg per day. The cost is nearly identical between iHerb ($71.37) and Amazon ($71.97) but slightly less expensive on iHerb. On Amazon, it ships from a third party and is not eligible for Prime. Free of GMOs, soy, and other common allergens.

Natural MK-7 From Natto

Healthy Origins Vitamin K2 as MK-7 — 100 μg MK-7. 14 cents per softgel, 28 cents per day to get 200 μg . Less expensive at iHerb ($24.99) than at Amazon ($29.50). On Amazon, it is sold by Amazon and eligible for Prime. Beware of the subscription button, and beware of the bottle containing 60 softgels rather than 180, which is much more expensive per softgel. The company says this product comes from natto but is free of soy. It contains non-GMO corn starch, a potential source of allergens. This is the least expensive option from among the natto-derived supplements.

Sonora Nutrition Vitamin K2 Natural MK-7 — 100 μg MK-7. 18 cents per capsule, 36 cents per day to get 200 μg. Available on Amazon, where it is fulfilled by Amazon and eligible for Prime free one-day shipping. Presumably made from soy.

Natural Factors K2 — 100 μg MK-7. 21 cents per capsule, 42 cents per day to achieve 200 μg. $12.57 from Amazon. Derived from non-GMO natto. The company has a unique farm-to-capsule model where it controls everything that goes into its supplements from the soil to the encapsulation.

Nature’s Plus Source of Life Garden Vitamin K2 — 120 μg MK-7. 22 cents per capsule. 43 cents per day to obtain 240 μg , 37 cents per day to take an average of 200 μg . Less expensive on Amazon ($12.95) than iHerb ($15.13). On Amazon, fulfilled by Amazon and eligible for Prime. Contains a blend of plant, mushroom, and algae extracts. Certified organic, certified non-GMO, certified allergen-free.

Now Foods MK-7 Vitamin K2 — 100 μg MK-7. 21 cents per capsule, 42 cents per day to get 200 μg . 19 cents per capsule, 38 cents per day to get 200 μg. Less expensive at Amazon ($11.46) than at iHerb ($12.73). On Amazon, it is sold by Amazon and eligible for Prime free one-day shipping and Amazon Fresh, but beware of the subscription button. From non-GMO natto. Contains soy. Does not contain other common allergens but processed in a facility where other allergens may be present.

Nutrigold Vitamin K2 MK-7 Gold — 100 μg MK-7. 23 cents per capsule, 45 cents per day to get 200 μg. $27.99 from Amazon. Sold by Amazon and eligible for Prime, but beware of the subscription button. Non-GMO. Made from soybeans, but free of allergenic soy protein. Free of other common allergens as well, verified by third party testing.

Natural Factors D3 & K2 — 1000 IU vitamin D, 120 μg MK-7. 35 cents per softgel, 58 cents per day taken to average 200 μg/d, or 70 cents per day to yield 240 μg. Identical in price ($20.97) between Amazon and iHerb. MK-7 is derived from non-GMO natto. The company has an unusual farm-to-capsule model where it controls everything that goes into its supplements from the soil to the encapsulation. Taken to yield an average daily dose of 200 μg K2/d, it yields 1,667 IU vitamin D; taken twice a day to yield 240 μg K2, it yields 2000 IU of vitamin D, both of which are more than the 1,000 IU of vitamin D in Thorne Research D/K2. However, the Thorne product contains MK-4 and this product contains MK-7. This is the only product that combines relatively high doses of vitamin D and MK-7.

Jarrow Formulas MK-7 Vitamin K2 — 90 μg MK-7. 20 cents per softgel. 42 cents per day to get 180 μg, 47 cents per day to average 200 μg. Less expensive at iHerb ($12.48) than at Amazon ($13.55). On Amazon, it is sold by Amazon and eligible for Prime free one-day shipping and Amazon Fresh, but beware of the subscription button. From non-GMO natto. Contains soy but free of most other common allergens.

Carlson Labs Vitamin K2 MK-7 — 45 μg. 13 cents per capsule, 53 cents per day to get 180 μg, 67 cents per day to get 225 μg. Less expensive buying a 180-capsule bottle from iHerb ($24) than the 90-capsule bottle sold on Amazon ($15.23). On Amazon, sold by Amazon and eligible for Prime free one-day shipping and Amazon Fresh, but beware of the subscription button. Made from natto and contains soy, though their own web site suggests they may have switched to chickpea.

Bluebonnet Nutrition Vitamin K2 — 100 μg. 32 cents per capsule, 64 cents per day to get 200 μg. Almost identical in price between Amazon ($32.39) and iHerb ($32.40). On Amazon, fulfilled by Amazon and eligible for Prime, but beware of the 2-bottle package that is more expensive and not eligible for Prime. Made from natto. Non-GMO, Kosher, contains soy but free of other common allergens.

Nature Made Vitamin K2 Softgel — 100 μg. 52 cents per softgel, $1.03 per day to get 200 μg. $15.45 on Amazon, where it is sold by Amazon and eligible for Prime. Made from “natto organism,” and contains soy.

High-Dose MK-4

Supplements where the lowest dose contains 5 mg or more of MK-4 are included in this section. It is impractical to use these supplements to reach an average dose of 200 μg/d. They are primarily useful as a means of reaching the pharmacological dose of 45 mg/d that has been used to treat osteoporosis, to prevent the occurrence of hepatocellular carcinoma in women with viral cirrhosis, and to prevent the recurrence of the same disease in people who have already been treated for it. Although high-dose MK-4 supplements are available over-the-counter and have a low risk of side effects, these treatments are pharmacological rather than nutritional in nature. Therefore, I recommend using them under the supervision of the physician who is overseeing treatment for one of these conditions.

Advanced Orthomolecular Research Peak K2 — 15 mg MK-4. 35 cents per capsule and $1.04 per day to reach 45 mg. Less expensive on Amazon ($31.30) than iHerb ($34.56). On Amazon, fulfilled by Amazon and eligible for Prime. Free of common allergens.

Note: This company also makes a low-dose supplement, but it can't be ordered online and the company is not transparent about its price, so I am not including it in this review.

Relentless Improvement Vitamin K2 — 15 mg MK-4, 60 μg MK-7. 39 cents per capsule and $1.17 per day to reach 45 mg. $34.95 per bottle on Amazon, where it is fulfilled by Amazon and eligible for Prime free one-day shipping. Taken to provide 45 mg/d MK-4, it also provides 180 μg/d MK-7. While research suggests that MK-4 and MK-7 have different tissue distributions at low doses, it is unclear whether there is any benefit to adding a low dose of MK-7 to a far higher dose of MK-4. The vitamins are synthetic and the company guarantees a low percentage of inactive cis isomers.

Carlson Labs Vitamin K2  — 5 mg MK-4. 18 cents per capsule and $1.66 per day to reach 45 mg. Less expensive on Amazon than on iHerb. On Amazon, the 60-capsule bottle ($10.99) and 180-capsule bottle ($33.26) are both equivalent in price per capsule. Both are fulfilled by Amazon and eligible for Prime, and the larger one is eligible for Prime free one-day shipping. Be careful of the subscribe and save button on the smaller bottle. iHerb only sells the 60-capsule bottle ($14.94).

Food-Based Supplements

Supplements included in this section are those that isolate a food oil itself or a major fraction thereof rather than specifically isolating one or more forms of vitamin K2. The nutrients in these supplements are less concentrated, but they are present in a broader network of synergists. While vitamin K2 supplements are a great way to optimize vitamin K status in someone whose diet is otherwise good, food-based supplements are likely to be better ways of compensating for an otherwise suboptimal diet.

Walkabout Australian Emu Oil — 40 cents per gram as a liquid oil, 52 cents per gram as capsules. Each capsule contains one gram of total oil and 4 μg MK-4. This product is not available on Amazon or iHerb. Its price is identical between Radiant Life, where the liquid oil ($45) and capsules ($52) can be ordered on the same page, and Corganic, where the oil and capsules are available on separate pages. Additional shipping charges apply to both sellers. Shipping charges for RadiantLife would be $7.95 for the liquid oil, $9.95 for the capsules, and free for a total order over $125. Corganic shipping charges depend on your address. Reaching 200 μg K2/d with this product would require 48 capsules or 3.5 tablespoons per day of the liquid oil and is obviously impractical. However, five capsules per day would yield 20 μg/d; added to a nutrient-poor diet containing only 15-20 μg/d on its own, this would double a person's Kintake. The oil also naturally contains a blend of essential fatty acids and other fat-soluble vitamins.

Green Pastures X-Factor Butter Oil — 43 cents per capsule, with each capsule containing 0.5 grams of oil. Less expensive on Amazon ($43.20) than on the Green Pastures web site ($60). On Amazon, fulfilled by Amazon and eligible for Prime free one-day shipping. However, the Green Pastures web site offers liquid oils as well as capsules and offers a greater diversity of flavors than available on Amazon. Each capsule contains 0.4 μg of K2, mostly as MK-4. Reaching 200 μg/d would require 500 capsules per day and is obviously impractical. However, Green Pastures has in the past reported an unidentified set of quinones in the oil, which could upon further testing be shown to have additional vitamin K activity. For example, the fermentation of the oil could produce tetrahydromenaquinones, which are found in high concentrations in certain cheeses but have not been measured in the butter oil. The oil also naturally contains a blend of essential fatty acids and other fat-soluble vitamins.

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Light and Heat Stability, and Proper Storage of Vitamin K2

Vitamin K is only slightly sensitive to heat, but is extremely sensitive to light. So much so that when we measure vitamin K in a laboratory we work under yellow lamps. In food oils exposed to daylight, 80 percent of the vitamin K disappears within two days. To make sure that your food and supplements retain their vitamin K content over time, keep them in the refrigerator, behind cabinets, or otherwise out of the light when not in use. If you keep them in plain daylight, they should be in amber glass or in opaque containers such as the white plastic used for most supplements.

How Much Fat to Eat With Vitamin K2 and What Kind

Vitamin K is fat-soluble so fat helps us absorb it from foods and supplements. If your fat intake varies from meal to meal, it makes sense to eat your K2-rich foods or take your K2 supplements with the meal that contains the most fat. The optimal amount of fat to maximize absorption of K2 from a single meal is probably about 35 grams. The true optimal amount of fat has not been precisely determined and may be higher than this, but I consider it adequate.

For the best effect, the fat should be low in polyunsaturated fatty acids, which means that butter and other animal fats, tropical oils, olive oil, avocado oil, macadamia nut oil, and the high-oleic varieties of sunflower and safflower oil would help the most. By contrast, soybean oil, canola oil, the regular varieties of sunflower and safflower oil, grape seed oil, and most other oils derived from nuts and seeds would help the least.

Notably, many of the foods richest in K2 like cheese, meat, and egg yolks are themselves rich in fat. The total fat content of the meal is what is important, so the more natural fats within the foods, the less you have to add.

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Vitamin K Absorption and Fat: A Closer Look

Dietary fat is important for the absorption of all fat-soluble vitamins partly because it helps dissolve the vitamins and partly because it helps stimulate the machinery involved in fat digestion, such as bile acids and lipases. Studies have generally suggested the following rule: the more fat you eat, the more fat-soluble vitamins you absorb. For example, 28 grams of fat allows better absorption of carotenoids from a salad than 6 grams of fat (Brown, 2004), and 30 grams of fat allows better absorption of vitamin E from a supplement than 11 grams of fat (Bruno, 2006). Studies have also shown that oils lower in polyunsaturated fatty acids (PUFAs) promote better absorption of fat-soluble vitamins than high-PUFA oils. For example, beef tallow allows better absorption of beta-carotene from a standardized test meal than safflower oil (Hu, 2000).

These rules appear to apply to vitamin K just the same. For example, 35 grams of fat allows better absorption of MK-4 than 20 grams of fat (Uematsu, 1996), and more K1 is absorbed from spinach with 25 grams of butter than without butter (Gijsbers, 1996). More K1 was absorbed from a “cosmopolitan” meal or an “animal-oriented” meal than from a “convenience meal,” with one possible explanation being the two-fold greater PUFA content of the convenience meal (Jones, 2009).

None of these studies showed a ceiling to the fat effect, and none of them tested more than 35 grams of fat. So, there may not be any ceiling to the effect. What we can say with confidence is that 30-35 grams of fat will provide for better absorption than lower amounts. Even still, absorption will probably never reach 0% or 100%, and for any given percent absorption one can always absorb a greater total amount of a vitamin by consuming more of it. Therefore, there is no sense in chasing after complete absorption and there is no intrinsic danger of a low-fat diet. If you have a good reason to eat less than 35 grams of fat per meal, it just becomes more important to spend the fat you do eat wisely by allocating it to K2-rich foods. It is fine to be flexible about fat intake, but it is important to be aware that any given amount of K2 in the diet will provide more nutrition to our bodies if consumed with a good dose of healthy fat.

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How to Test Your Vitamin K2 Status

Unfortunately, there are no useful tests for measuring vitamin K status that are available to the general public at this time. However, good tests are on the horizon. VitaK will be releasing innovative medical devices to allow health care practitioners to monitor vitamin K status in patients, and ImmunoDiagnostic Systems will be releasing a blood test for dp-ucMGP, a protein that circulates in the blood when blood vessels become deficient in vitamin K.

If you would like me to notify you when these tests become available in the United States, please join my newsletter.

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Tests for Vitamin K Status: A Closer Look

Vitamin K travels through the blood almost entirely as a means of being delivered to our other tissues, so blood levels of vitamin K only reflect recent intake rather than long-term nutritional status. Red blood cells lack the organelles in which vitamin K function is important (the endoplasmic reticulum, mitochondria, and nucleus). Lymphocyte vitamin K concentrations could, perhaps, reflect long-term vitamin K status, but practically nothing is known about what vitamin K does in lymphocytes in the context of human nutrition, and such tests have never been validated to show anything important.

The appropriate way to test vitamin K status is to look at the carboxylation status of vitamin K-dependent proteins. These tests can be validated by showing that they respond to vitamin K depletion or supplementation and that they correlate with known health outcomes that respond in the same way. For example, the ability of the blood to clot reflects vitamin K status in the liver, where clotting factors are made; the carboxylation status of osteocalcin reflects vitamin K status in bone, where osteocalcin is made; and the carboxylation status of matrix Gla protein (MGP) reflects vitamin K status in blood vessels, where MGP is made.

Clotting disorders are life threatening and we have known about the role of vitamin K in this process for almost a century. As a result, a whole battery of tests for the different vitamin K-dependent clotting factors are readily available (for example, Ohishi, 2014). Vitamin K1 is perfectly good at supporting the production of clotting factors, and since hemorrhage can be life-threatening, clotting factors will always get priority over a limited pool of vitamin K. Thus, most people consume enough vitamin K for their clotting factors to be fully carboxylated and these tests are not useful measures of whether vitamin K status is adequate to support its other functions in other tissues.

The most common marker of vitamin K status in research studies is the carboxylation status of osteocalcin, which reflects vitamin K status in bone. This test is only useful if the proportion of osteocalcin in the carboxylated and undercarboxylated forms can be measured. Unfortunately, this is not available outside of research studies. Quest offers total osteocalcin, but doesn’t measure its carboxylation status; Genova offers undercarboxylated osteocalcin, but doesn’t measure the total. One could “hack” its carboxylation status by getting both, but this would require each “half” of the correct marker to be measured from separate blood samples analyzed by separate laboratories, making the interpretation highly questionable. Were it available, we would still have to interpret it with caution, because, independent of vitamin K status, bone resorption decarboxylates osteocalcin and releases the undercarboxylated form into the bloodstream where it has beneficial hormonal roles, so it isn’t a black-and-white marker of vitamin K status.

The most promising marker of vitamin K status on the horizon is desphospho-uncarboxylated matrix Gla protein (dc-ucMGP), which reflects vitamin K status in blood vessels and the risk of soft tissue calcification. It’s just a matter of time before it becomes available.

Click here to close the detailed explanation.

Is Vitamin K2 Dangerous?

Very high doses of vitamin K2 have proved remarkably safe in large clinical trials, but there are safety concerns for people taking prescription anticoagulants, and there are reasons to be cautious about high doses even for healthy people.

This is Critical If You Are Taking Prescription Anticoagulants

The most common anticoagulants used in medicine are warfarin and its relatives. As a class, they are known as 4-hydroxycoumarins. These go by a number of brand names, the most common of which is Coumadin. As a class, these drugs act as vitamin K antagonists, and it is absolutely critical that anyone taking them avoid making any changes to their diet or supplements that would be expected to change their vitamin K intake except under the strict supervision of the physician who prescribed the medication.

Hypothetical Side Effects of High Doses

Long-term use of 45 mg per day of MK-4 has not revealed any established toxicity syndrome or risk of serious side effects. This is 225 times the dose I recommend. Nevertheless, the biochemistry of vitamin K suggests that unnecessarily high doses could rob the body of antioxidants or interfere with blood sugar regulation, insulin sensitivity, and hormonal health. The real question, though, is at what dose these potential side effects kick in. Since 45 mg per day has not shown any clear syndrome of toxicity and the dose I recommend is more than 200 times lower than this, I think we have a very large window of safety to work within. The potential for hypothetical side effects, however, should lead us to avoid supplementing with doses that are much larger than those that provide clear benefits.

Click here for a more detailed explanation.

Hypothetical Side Effects of High-Dose Vitamin K

There are several aspects of vitamin K’s biochemistry that suggest high doses could have adverse effects on our health:

  • Vitamins E and K are broken down in similar pathways (Shearer, 2008). High doses of either one elicit an increase in these catabolic pathways by activating a common receptor known as the steroid and xenobiotic receptor (SXR) or the pregnane X receptor (PXR). As a result, high doses of one will elicit the destruction of the other. Thus, high-dose vitamin K could contribute to vitamin E deficiency.
  • Second, a small portion of vitamin K is broken down to a compound known as menadione (Thijssen, 2006). Some of the menadione is used to synthesize MK-4, but high concentrations are toxic. We therefore conjugate a portion of the menadione to glutathione, the master antioxidant and detoxifier of the cell, and excrete the complex into our urine. High doses of vitamin K could therefore deplete glutathione. This would impair detoxification, and along with vitamin E depletion it would hurt antioxidant activity.
  • High doses of vitamin K can inhibit bone resorption, which is probably the mechanistic basis by which 45 mg/day reduce fracture risk (Iwamoto, 2013). While bone resorption sounds like a bad thing, we need to use it every day to help our bones remodel themselves and adapt their structures to our lifestyles, and to keep blood levels of calcium within a precisely controlled range. We also use bone resorption to release osteocalcin into the blood, where it acts on multiple tissues to improve our metabolic and hormonal health (Ferron, 2007; Oury, 2013). Ironically, one of the benefits of vitamin K2 is to support proper production of osteocalcin, but high doses of the vitamin could hypothetically prevent us from using it. That would be expected to hurt blood sugar control, insulin sensitivity, our metabolic rate, and, in males, testosterone production.

Japanese trials using 45 mg/day MK-4 to treat osteoporosis have not established any risk of severe side effects (Iwamoto, 2013). Most of them, however, had between 20 and 120 subjects per group. One very large two-year trial with over 2,000 subjects per group (Inoue, 2009) reported 23 percent more adverse drug reactions in the MK-4 group than in the control group. The report did not include any description of what those side effects were, but confirmed that there was no difference in “serious” adverse effects or deaths.

Such high doses are pharmacological in nature and not nutritional. We should look at their costs and benefits in the same way we look at other pharmaceutical drugs. In this light, high-dose MK-4 is remarkably safe and effective. We nevertheless have hints that negative side effects of some sort occur when using extended pharmacological doses and we have several biochemical rationales for why high doses would cause harm. This provides a basis for caution in using doses outside of the nutritional range.

Click here to close the detailed explanation.

Vitamin K2: A Critical Component of a Well Rounded Nutrient-Dense Diet

Vitamin K2 is something most of us could use a lot more of. The best way to obtain it is to consume K2-rich foods in the context of a well rounded, nutrient-dense diet. The many other nutrients contained in a good diet provide the context that makes vitamin K2 safe and effective. Supplements can be very helpful, as long as they are used as adjuncts to support a good diet rather than as replacements for a good diet.

From here, you can leave a comment, scroll on for my suggestions for further reading, or search for some K2 rich foods in our database to plan out your next K2-rich meal.

Suggestions for Further Reading

In spring of 2007, I wrote “On the Trail of the Elusive X Factor: Vitamin K2 Revealed.” This is an extensive article arguing that vitamin K2 was the “activator X” that Weston Price claimed to have discovered in 1945. Weston Price was one of the pioneers of nutritional anthropology, and many people had speculated about the identity of his “activator X” for decades. The article tells the history of that mystery and in the process extensively reviews the many roles of vitamin K and its interactions with other important nutrients like vitamins A and D.

For more about how vitamin K interacts with other nutrients in the diet, see my 2013 article, “Nutritional Adjuncts to the Fat-Soluble Vitamins.”

For my other writings on vitamin K2, see Start Here for Vitamin K2.

Some other sources that I recommend include Chris Kresser’s Vitamin K2: The Missing Nutrient, and Stephan Guyenet’s writings on the topic. Kate Rheaume-Bleue wrote a great book, Vitamin K2 and the Calcium Paradox: How a Little-Known Vitamin Could Save Your Life.

For a more advanced understanding of vitamin K, I would start with the vitamin K chapter by John Suttie in Modern Nutrition in Health and Disease. I consider this textbook so valuable as a general scientific reference that I buy it again every time there is a new edition. Reviews by important figures in the field such as Martin Shearer, John Suttie, Sarah Booth, Cees Vermeer, and Leon Schurgers are also highly valuable and can be found on pubmed. On the specific topic of the hormonal functions of osteocalcin, I recommend reviews by Gerard Karsenty, also found on pubmed. Finally, the expandable “detailed explanation” sections within this resource are rich in scientific references that provide additional opportunities for advanced learning.

I’d Like to Hear From You

I would like to make this a multi-purpose resource for all things related to vitamin K2 that can be constantly improved over time. Therefore, I’d like to hear from you: what is most useful? What can be improved? What topics would you like to see included in the future? What features would you like to see added to the searchable database? Please let me know in the comments.

The Database: Search for the Vitamin K2 Contents of Foods

Here’s the icing on the cake. We scoured the literature for data on the K2 contents of foods and found many publications that haven’t been included in databases elsewhere. There are almost 200 foods included. You can search by keyword, or you can submit a blank search to browse through everything. You can pick a food category and search it by keyword or submit a blank search to browse through just the foods in that category. Every food entry gives you the opportunity to click for more details, including a breakdown of its different vitamin K forms and the reference from which the data comes. Have fun searching!

Vitamin K2 Advanced Search Form


This resource is continually updated so that it will remain the most useful resource on vitamin K2 over time. Click below for a list of updates.

Click Here for the Update Log.

December 29, 2016: Database Additions, Performance Enhancements, and Supplement Reviews

Improved Clarity to the Second Infographic

Several people found the third row of the second infographic, “Why It Matters What Type of Vitamin K We Eat,” difficult to read. We changed the font from all-caps to regular capitalization and made the background darker, and it is now much easier to read.

The Site Now Loads Three Times Faster

My site has, since it started, loaded rather slowly, and that's because I had a budget of near zero when I started it and got a deal of one year free hosting. Being free, it was nothing to complain about. However, The Ultimate Vitamin K2 Resource has a lot to load and is generating tons more traffic to the site, which means its time for an oil change. I migrated my site to WP Engine, which instantaneously cut the load times on my pages by 65%. WP Engine offers a lot of assistance in further optimizing your site for performance and speed. I have yet to take advantage of any of that, but hope to in January. Nevertheless, simply moving from one server to another has caused everything to operate at three times the speed.

My choice to move to WP Engine happened after a failed migration to another company's servers. I'll keep them nameless for the time being, but my own hastiness combined with their inadequate technical assistance and customer service caused my site to temporarily crash worldwide. I apologize to any of you who experienced any frustration as a result of this during the transition. The WPEngine migration was smooth as a baby's bottom for two reasons: first, most of it is automated with a fantastic plugin; second, their customer service is off-the-charts, with unlimited continuous access to both phone and live chat. While the downtime the site experienced is embarrassing to me, I'm incredibly happy with the end result. It's pricey, but I intend this site to be awesome in every way in 2017, and awesome content is only as awesome as the speed and performance of the site that hosts it.

The Vitamin K2 Searchable Food Database Now Opens in a New Tab

Originally, the searchable database opened in the same tab. If you wanted to do more than one search, you had to hit the back button, which brought you all the way to the top of the article. All this was far more terrible than it sounds, because the slow site speed prior to the WPEngine migration was causing each of these events to take 10 seconds! Imagine doing five keyword searches, with each search taking 10 seconds, each time going back to the page taking 10 seconds, and then going back to the database with several more seconds, depending on your scrolling skills. A nightmare.

Now, the database opens in a new tab, so you are never more than a tab-switch away from it for a new search. Plus, the site migration has made each keyword search load three times faster. Together, searching the database now offers a much better experience.

Emu Oil, Green Pastures Butter Oil, and Over a Dozen Other Foods Have Been Added to the Database

Many people requested data on Walkabout Australian Emu Oil and Green Pastures Butter Oil. These have now been added to the database. The data for these products comes from a set of foods sent by the Weston A. Price Foundation to VitaK for independent analysis. Since the foundation has made the original lab report publicly available, I was able to add these foods to the database and be confident that I was maintaining the same level of rigor as before. To date, every single entry in the database has the exact source of information available to the user simply by clicking on “view more details” under the specific result, and the sources come either from the peer-reviewed scientific literature or independent analyses documented with original lab reports.

Other foods added to the database include oysters, fish roe, shrimp, conventional and pastured chicken liver, cheeses and butters of different varieties with name brands or local farm sources listed, egg yolks, tallow, duck fat, lard, and cod liver oil. If you're salivating already, go on and search your heart out in the database.

10 Supplements Have Been Added to the Review

In response to audience requests, the following supplements have been added to the comprehensive review. I have not changed my top three recommendations in the main text. These include mixed MK-4 and MK-7 supplements, natto-derived MK-7 supplements, and an apparently synthetic MK-7 supplement. Additionally, I created two new categories: High-Dose MK-4, and Food-Based Supplements.

Mixed MK-4 and MK-7 Supplements

  • Pure Encapsulations Synergy K 
  • Maxx Labs Vitamin K2 Complex 

Natural MK-7 From Natto

  • Natural Factors K2 
  • Natural Factors D3 & K2

Synthetic MK-7 Supplements

  • K-Force

High-Dose MK-4

  • Advanced Orthomolecular Research Peak K2 
  • Relentless Improvement Vitamin K2
  • Carlson Labs Vitamin K2  

Food-Based Supplements

  • Walkabout Australian Emu Oil 
  • Green Pastures X-Factor Butter Oil 

January 16, 2017: Search by Specific Menaquinones

As of January 16, 2017, you can now choose which specific form of vitamin K2 you would like to search for. This will rank the foods displayed by that form. No matter which form you search and sort by, you can click on “view more details” for the full list of menaquinones, references, and other details.

Click Here to Close the Update Log.

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  1. Hi Chris, I have osteoporosis, I am looking for a cheese that is high in MK-7, I am already supplementing with MK-4, I am taking 45mcg, I am sensitive to all fermented foods and would like to eat some cheese to get my MK-7, could you please help me? Thank you Lori

    1. No it does not kill the K2… usually high heat and other manipulations can do so, for example, in most cod liver oils. Consider that cheese is a fairy good source of K2 (MK-4) but it also contains some higher chain Mk’s (not-7_

      some consume them raw and raw egg yolks from pastured chickens are the ultimate in nutrients; but they must be grown by a farmer you know and trust. Otherwise there may be risk of salmonella.

  2. I ordered a vitacost brand of vitamin K2 MK7 with nattokinase. It stayed in the mailbox for the entire day at 99° temperatures outside. Do you think that this would damage the supplement?

  3. Hello – I recently read an article about taking vitamin K supplements several hours apart from vitamin D supplements to avoid nutrient competition. Has anyone heard of this? I wish there was a test for vitamin K levels to check this out. I take most of my vitamin D along with other fat-soluble vitamins (including K) and my main meal, and my vitamin D levels are good, i.e. apparently not affected by taking it together with K, but do not know my vitamin K level to know if that is being affected.

    1. I have a supplement where the D3 and K2 are in the same capsule. There is not a direct test for K2. It is hard to take too much K2, and the supplementation I have read is 180 mcg a day. You can get k2 from fermented foods. If you take them with some oil even fish oil , I think you are just fine to take together.

  4. I really enjoyed the Vitamin K podcast, this article, and the searchable database. I was at first excited to see that natural emu oil appeared to be a great natural source of Vitamin K because I thought I could pop a couple of emu oil pills and be good. Then I considered that 50 g of emu oil is a lot harder to consume daily than 50 g of pork sausage, so I think I’ll try to get a combination, along with green leafies. Although kind of nasty to hear your insight about why pork may have higher MK-10 levels than other meat. Yuck. I agree – it would be interesting to hear if humanely-raised pigs in more spacious locations would have lower MK-10 levels.

    Super cool to learn that biotin and Vitamin K are the only vitamins that handle carboxylation.

    Also very interesting to hear that MK-4 helps turn off cancer-promoting genes and turn on sex-hormone related genes. Also interesting that statins downregulate the conversion of K1 to MK-4, which implies that statins can increase our cancer risk and decrease our sex hormone production. Considering also statin’s downregulation of the building blocks that make sex hormones, that’s a double whammy effect of statins having a potential negative impact on sex hormone production.

    I loved learning from your site and a research article that Matrix GLA protein (MGP), is the most potent inhibitor of tissue calcification and is activated through 1) phosphorylation and 2) carboxylation, and the carboxylation status is the result of vitamin K levels. So interesting to realize that adequate Vitamin K levels help solve two common problems: soft tissue calcification and osteoporosis.

    Finally, I’m a big fan of Weston Price, so fun to learn more about Activator X. Thanks so much for all your research!

  5. Hi, Great info. I’d like to add to the supplement list a review of rnareset’s D3 K2. Thanks. Dr. Dean wrote The Magnesium Miracle and has formulated her own high quality supplement line. Thanks.

  6. Interested in D3 and calcium and K2. As an older female….BUT…I have Alpha Gal Syndrome…everything that goes into my body must be mammal free…including by products

  7. My understanding is that pantaprozole interferes with absorption of K2. Thus one should take K2 before taking pantaprozole which takes about 30 minutes to take effect.. Is this correct? .Any other comments re K2 and pantaprozole will be appreciated.

  8. I have been following this Activator X/vitamin K2 business ever since I read Price’s book about 30 years ago and your work identifying it as K2 in 2007 and Rheume-Blue’s book. I am a retired research biochemist with a background in blood clotting (I purified and characterized several of the vitamin K dependent clotting factors and their inhibitors) and also worked in the biotech industry developing viral diagnostics and vaccines using recombinant proteins. I wish that there were (more) studies identifying all of the places in the body where the various vitamin K2 types partition as well as their circulating lifetimes/halflives. I know K4 does get into the brain and I remember Price suggested that it can be found in the saliva. But it would be very useful to know if there is/are other organs that it has a preference for.

  9. I tried k2 mk7 sports research and had chest pain. I’m going to try k2 from natto supplement. Thank you for guide for k2

      1. our product (vK2) contains both MK4 and MK7. Unlike most other formulas our ingredients are pharmaceutical grade (with NO Chinese sourced ingredients and with with a VERY high percent of the bioactive “trans” form).

  10. Hello Mr. Master John,
    I have come upon a vitamin K supplement that isn’t into your list and looks intriguing! It is called Koncentrated K and contains high dosage MK-1, MK-4, MK-7 and astaxanthin. Being a WAP member and follower, I’m hesitant taking it without knowing more about it. The price is quite appealing. I do eat butter oil, natto, cheese and dessicated organ tablets along with astaxanthin, which of course isn’t cheap. I’d so appreciate it your input on this product
    Thank you so much

    1. I’m no expert on anything, just a layman; I’ll do what I can. I’ve been taking Kon-K for a year or two. I can assure you it’s a legitimate product and is safe. Whether it actually does anything is like all the other supplements I take–I can only hope something good metabolically is happening in my body.

      The people at Innovix Labs will tell you that the MK-4 dosage is way too high without benefit, and maybe the MK-7 dosage as well. I spoke with the man at Kon-K about the astaxanthin dosage being low compared to a recommended dosage of 12mg (I think is the number) by True Health, and he gave me a technical answer I didn’t understand.

      Your comment way below imbedded in comments from 2016 probably won’t be seen by many people. And Chris Masterjohn doesn’t seem to be active here anymore, so don’t expect to hear from him. Finally, clicking on the link in the email informing me of new comments here about managing my subscription now results in a page-not-found message. Not sure if this website is a “going concern” anymore.

      Good luck.

    2. Koncentrated K is 50%/50% trans/cis so the active dosage is inflated. Trans (active form) should be in the high 90s. Also, they claim natural source for the MK4. Not possible.

  11. Whoa. Over 1200 comments, I can’t possibly find the answer I’m looking for, lol.

    I have a D3/K2 liquid supplement I bought because calcium needs both for optimal absorption. Unless you said otherwise and I missed it.

    Now I’m not sure I was providing enough dietary fat at the same time the D3/K2 was taken. I know fat is needed. I didn’t know how much until your article. Can D3/K2 be taken (with fat) separately from calcium? As long as they’re in the same day, it’s okay? Or do they all need to be in the same meal?

    1. It is better in the same meal. It is better to talk D3/K2 with a meal that has some fat. It can be whole greek yogurt.

  12. Is consuming Natto not recommended for individuals with an increased prothrombin gene mutation or would the fibrinolytic aspect balance out the K2 increased prothrombin?

  13. Rarely find informative articles like this. Everyone ends up spending a lot of money on diseases nowadays. So better we know what actually makes us ill and try to avoid unnecessary things from our healthy life.

  14. This was really good, I did study K2, and you gave so much more information on it all, Im glad to see my diet is spot on and I do take d3 k2. I also love it when an expert like you dont poo poo good healthy animal fats. I think that reducing your good fat intake is a disaster for your health

  15. How long is Thorne k2 likely to last in fridge?
    To have 1c per day it needs to last something like 20 years.

    1. I would think that is an expiration on the bottle. I would not go much beyond that because of the oxidation of K2. In the fridge. Are there other people in the family you can share with?

  16. when i click on; “Carson Labs Vitamin K2 MK-7” link, at the beginning of the paragraph, it takes me to iHERB instead.

    1. Thank you for your comment! I found your video very informative!!! I’ll link it for others below. My husband has a huge jaw cyst (silver dollar) that will need to be decompressed with a drain over the course of a year while hopefully regrowing his jaw bone back. Right now it is eggshell thin. I bought the designs for health D supreme that has D3K1/K2/ GG. Would you recommend this or following the osteoporosis protocol? He’s 42.

  17. Thanks for such an informative document. I had been trying to find something like this. I have been living a pro metabolic lifestyle with food and avoiding stress, toxin, and following Dr Ray Peat. It had been suggested to take asprin daily as a anti inflammatory, to assist with health especially in our current times. I was also advised to take vitamin k with the asprin to assist with the blood thinning. Do you have any information on this? I bought Health Natura True K2 which has K2-Mk4 in mct oil, 1mg per drop. I am still trying to figure out how much to take with the asprin. I’m having trouble finding information that is in laments terms 😊 thanks again

  18. I think more attention should be paid to K1 when it comes to coronary artery calcification:

    “Research suggests that vitamin K1 supplementation does not have cardiovascular benefit in healthy people, but, in people with existing coronary artery calcification, it may help slow progression. For example, one study in Boston showed that people with pre-existing coronary artery calcification who took a multivitamin including vitamin K1 for three years had 6% less progression of calcification than those who received the multivitamin without K1. However, among people without pre-existing calcification, an equal percentage developed calcification regardless of whether or not they received vitamin K1 (Shea, Am J Clin Nutr 2009). A study in Australia investigated the effects of vitamin K1 supplementation in men and women (average age 66) with type 1 or type 2 diabetes and moderate coronary artery calcification, half of whom were also given the anti-inflammatory drug colchicine (which can reduce the risk of heart attack and stroke in people with coronary artery disease). The study found that 10 mg of vitamin K1 taken once daily for three months decreased the risk of developing new calcified lesions in the coronary arteries and aorta, respectively, by 65% and 73% compared to placebo. These decreases were similar for those taking or not taking colchicine (Bellinge, Am J Clin Nutr 2021).”

  19. Any information or thoughts on K for DISH (Diffuse Idiopathic Skeletal Hyperostosis)? Also, NAFLD with multiple liver cysts?

    If so, what forms would be most beneficial?

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    1. The main source of K2 in this study was hard cheese, which is high in saturated fat. Saturated fat has been shown to be associated with increased cardiovascular risk, so unfortunately this introduces a confounding variable that is proportional to the variable of interest (K2), making the study’s association difficult to interpret.

      1. Howard, that is a persistent and debunked myth lingering from a very flawed study the 50’s. The truth is that saturated fats are the healthiest fats . . .it is the vegetable/seeds fats that are very harmful . . . and of course trans fats are the worst things you could put in your body

  21. Hi Chris!!

    I’m pretty new to all of this but I’m working on my dental gum health and am trying to incorporate more ADK vitamins into my mostly carnivore diet. I’m doing my best with food but I’m trying to supplement with Rosita Cod liver oil and was wondering what you think of Green Pastures x-factor High vitamin butter oil? Also, any thoughts on K2 dosages for children? Thanks!

  22. A great resource and so well set out, thank you for making it available.
    I remain unclear though on the bodies synergy between D3 and K2. Does K2 rob the body of D3 or otherwise affect absorption of D3. Can they both be taken together? I see that some of your recommended supplements contain both D3 and K2 which would suggest there is no conflict between the two vitamins?

  23. Thank you,. This is the most explicit in depth article I have seen
    Would you be able to expand on the origin of the various ‘High Dose MK4 supplements’ and whether they are natural, synthetic or synthetic/bio-identical ?

  24. I need to take K2 MK7 as I have high level osteopenia but I also take an 81 mg aspirin a day as the hole in the heart that usually closes at birth left a very small hole. None of my doctors can tell me if there is risk in taking K2 MK7 while also taking low dose aspirin. Help!

    1. Kim, I assume the aspirin you take is to counter blood clotting. That being the case, Vitamin K2 would not be contraindicated, as it has nothing to do with blood clotting (vitamin K1 would be contraindicated).

  25. I am 65 and have osteoporosis. In December 2019 I broke a vertebrae. That wasn’t diagnosed until the following February, which led to the OP diagnosis in March, followed of course by the pandemic. Tried Fosomax for 4 weeks. Never again. Since then I’ve used a natural approach, diet exercise and supplements, mixed results. I’ve started having really bad reflux this past year. I just now realize the supplements may have chick peas in them, which I have reacted to quite severely in the past. So now I’m taking a break from any supplements with K-2. Any suggestions? Thank you.

  26. Hello! I read with interest your information on vitamin K in it’s myriad forms, and I think it is helpful, thank you very much! I am looking for a dose to treat a patient with recurring kidney stones. If that is a higher dose than the 100-200mcg/day, how long should the higher dose be maintained?

  27. What do you think of HumanN D3.K2 supplement. I just ordered 1 jar but concerned its not what I need.

  28. I had Pulmonary Sarcoidosis in the past and it is now in remission (after 2.5 years). I was advised by my pulmonologist to not take Vitamin D because of this illness as it can create hypercalcimia. When I read about K2, it’s always in conjunction with D3. My question is, can I take K2 alone without taking Vit D3?

  29. Would you please help me with this confusing information about Vit. K, 1 and 2? One nutrition website I saw recently (run by a chemist marketing her own line of supplements) says they won’t sell a vit. d supplement with vit k added, because the two together will increase the amount of calcium in the body and vitamin k thickens the blood, because of the clotting factor. Another forum of hypothroid sufferers were sharing with each other that one of them was supplementing with K and she got a clot in her right coronary artery. Her cardiologist blamed the vit K. She said, “If you look it up you will find any form vitamin K causes clotting. It increases the fibrinogen level in your body and if you are prone to clotting it can be dangerous. I would suggest having your fibrinogen level checked. Mine was high with taking the K2..” After reading this, I asked a pharmacist about vit. K and he said he “doesn’t like it, because it thins the blood” (I guess he means it interferes with people on blood thinners).

    Would you please clarify these confusing and contradictory claims? Clotting? Thinning? Are any of them at least partly true? I’ve been taking a D supplement with vit. K2, but it is only 10 mcg per capsule. I’ve been wanting to increase to at least 100 mcg, but these contradictory notions made me pause. Thank you very much.

    1. Kristen, I can certainly understand you being confused, as there is so much conflicting “info” out there.
      One point, I hope to clarify is that, vitamin k1 is involved in blood clotting not vitamin K2. Another point I want to make is that the popular chemist who has her own vitamin line says she won’t market a D3 supplement with added K vitamins, because “it would increase the amount of calcium”, it would “thicken blood”, “cause kidney stones”, Is not correct.

      I suggest you take a look at out site (yes we sell our own Vitamin K2 product too)

      I think you will find lots of very useful info

  30. I found your site after becoming confused by lots of conflicting information about vit. D3 supplementation along with Vit. k2 MK7. I wrote out my questions and posted my comment, when I wanted to add another comment correcting something I said. Then my first comment, being moderated, had disappeared. I’m sorry.

  31. I found your site today because I was trying to resolve the confusion I have now about vit.K after reading so many contrasting opinions and information. I am chronically low in vit. d, so I had been supplementing with a 500 iu D3 / 10 mcg K2 mk7 capsule. Trying to understand how the two work together, and interested in preventing calcium from ending up in my arteries, I was about to increase my K2 to 100 mcg, when I found a few different sites saying contrary info. A popular chemist who has her own vitamin line says she won’t market a D3 supplement with added K vitamins, because “it would increase the amount of calcium”, it would “thicken blood”, “cause kidney stones”, etc. “you only need D to increase D”. A thyroid forum had several people sharing that vitamin k causes blood clots, because of fibrinogen levels. Another author talked about carboxylating MGP. A Portugese doctor treating patients with high dose Vit. D therapy and vit. K stipulates avoiding all calcium foods while taking vit. D and closely monitoring calcium levels with blood and urine tests… Others wrote horror stories about damaging their kidneys from high doeses of vit. d, but they didn’t mention if they had taken vit. k.. I am paralyzed now and afraid to eat or take a supplement. Was any of the above true? How can I know? Every person who writes on the internet writes with authority yet completely contradict each other.
    When doctors or nutritionists advised me to supplement with vit. D, most of them said nothing about K, and other than measuring my D levels to see if the supplementation had worked to improve that level, none of them told me to monitor calcium levels.

    I would dearly appreciate some clarity here. Thank you.

    1. Thank you for all the challenging questions. Yes, between promotion of commercial vitamins, medical opposition to vitamin use, and simplistic thinking there is more confusion over the science of the vitamin K & K2 forms than just stupidity, it is driven at times by diverging fiscal interests. You literally have to be a better scientist than the people you are reading or talking to. You have my every compassion in this.
      First, vitamin supplements are safe. Most years NO deaths are accorded to vitamins in toxicology data reports with vitamins being ten times safer than the risk of being hit by lightening and a thousand times safer than taking acetomeniphen.
      The medical references on vitamin D are blazingly unscientific with Institute Of Medicine pronouncements of 600 IU daily doses being without scientific credit when compared with calculated 8895 IU and 9122 IU daily doses from the SAME Institute Of Medicine data that were published in two peer reviewed Journals. The IOM has been asked multiple times to review their numbers by research scientists. If you get your blood level for vitamin D tested, aim for a 50 to 70 ng/ml blood level for normal health, up to 200 ng/ml for reducing autoimmune symptoms. Generally start with the 10,000 IU and then adjust as needed. Doses under 30,000 IU are generally safe especially if some Retinol vitamin A is taken as low Retinol is a cause of kidney stones, not vitamin D. Doses above 30,000 IU should be managed by a physician who is trained in the Coimbra Protocol for high dose vitamin D used to suppress autoimmune conditions.
      Cofactors that work with vitamin D are 200-600 mg magnesium, 12-30 mg boron, 15,000 IU Retinol vitamin A, 20-30 mg zinc, and MK4 vitamin K2.
      There is NO optimal dose of vitamins D and K2. Why? Personal doses of vitamin D vary by a factor of ten, making proportioning of the K2 impossible. The need for vitamin K2 varies from zero to 45 mg a day for serious cases of artery calcification and bone loss. The body makes MK4 vitamin K2 by converting vitamin K1 with MK4 production falling off with age. Those under 30 don’t need MK4 unless they are medical cases, but above 40 or 50 years an MK4 supplement is very useful. The MK7 form of vitamin K2 is made by bacteria, not the human body so we are badly adapted to use MK7 and it is much less effective than the MK4 vitamin K2 which is identical to what all animals make. The 100 mcg of MK7 vitamin K2 is ok as long as you are not part of the 10% of people who get anxiety, sleeplessness, and a thumping heart beat from taking it. Doses of the MK4 form are 1 to 5 mg for healthy people. The MK4 helps the body make its Matrix GLA protein work to remove calcification from the arteries and makes the Calcitonin with to rebuild bones with more tissue strength and better microstructure.
      Taking MK4 and MK7 is completely safe, no extra clotting has been reported at up to 135 mg per day. The same for regular vitamin K, it can potentiate fibrogen clotting protein up to 100%, but no increase past 100% is possible.
      For information on taking calcium, only 500 to 800 mg of calcium is needed with higher blood levels of vitamin D. The Coimbra Protocol calls for strong calcium reductions but only at medically high vitamin D intakes.
      So now you know that doctors have only a few hours of nutritional training and much of that is obsolete or even unscientific in places. Look up Life Extension magazine which works hard to get good references in its articles and treats Nutrition with the good science it deserves. Dr Andrew Saul at is a good source as is vitamin D wiki.

      1. Hi David, your reply is by far the best and easiest to understand. I too have been confused about what to do about taking Vit D and K2. Thank you again.
        Presently, I am taking Synergy from Pure Encapsulations.
        It has K1 500 mcg, K2- 1000 mcg MK-4, MK-7. 45 mcg and the mfr just added to this formula D3 1000 in it.
        I am also taking Dr. Mercola’s Vit D3, 1000.
        So a total of 2,000 of Vit D3.
        I am curious do you have a K2 that you may prefer and can suggest? I always try to look for clean vitamins with good fillers or no fillers.
        I have High Fibrinogen, which was over 600, and brought down to 346 with taking Inflamazyme.
        Your help would be greatly appreciated.
        Thank you so much,

      2. This comment is a general one for this topic and not necessarily directed at David. I interjected here only because I couldn’t figure out where/how to post an independent post on this page, although there is a statement by David as well as others that I wanted to comment to and seek alternate opinions of, specifically regarding to mk7 being converted to mk4 and one other note.
        Per a number of as well as this one ( they state that mk7 is indeed converted to mk4 and that mk4 supplementation had no effect or increase in blood levels of mk4. This article ( also directly mentions MenaQ7 which is supposed to be a 100 percent Trans form of K2 and derived from chickpeas vs natto eliminating any soy or Cis form concerns. It’s also been noted several places that mk4 is the form most used and accessible by the bacteria h.pylori and that those with h.pylori overgrowth would do best not to use mk4.
        I, like many others am very confused by all of this and curious if mk7 actually causes palpitations and insomnia or are those due to other factors and where is the scientific data vs the subjective users’ statements? There is so much speculation and so many financially incentivised and biased articles that I tend to lend my belief to the scientific based organizations and data.

  32. There’s a warning to avoid K2 supplements if on anti-coagulants, specifically cumadin/warfarin, but I was unable to find any specifics with respect to Apixaban/Eliquis. which is an anti-coagulant but works differently. (I take it for paroxysmal AFib.) I stated taking the one Innovix 100/500 soft gel 10 days before a PT-INR test and the result was within range (14.3 sec PT and 1.1 INR), but do not know if that means K@ is safe for it. I assume the concern is that K@ might adversely affect coagulation times or is there some other concern?. Can you point me to any specifics for Eliquis and K2? (My nutritionist and my nephrologist are unfamiliar with K2..) I see my cardiologist on 3/19 and would like to discuss. Also regarding the Innovix, your recommendation implies taking one pill every 3 days. to get to your recommended standard daily amount. With this regimen, do both MK’s linger long enough to last three days?

  33. Jarrow Formulas makes the MK-7 softgels in 180 mcg per softgel (MCT and olive oil) as well.
    I’m getting those for my mom, who seems to have a severe K2 deficiency at present since taking calcium is apparently giving her hypercalcemia where she can’t keep her balance when walking.

    some other interesting options to consider are
    Doctor’s Best Natural Vitamin K2 Mena Q7® plus D3 — 180 mcg – 60 Veggie Caps (1000 IU D3 + 180 MK-7)


    TrueVantage Vitamin k2 MK-7 Supplement 180mcg (which is cheaper but comes in dry capsules)

    am trying to find out more about sourcing and form of the MK-7 in Bronson Vitamin K2 (100 mcg MK-7)

    Lastly, if you need extra D3 and prefer liquid drops (I sure do, except maybe for travel, swallowing lots of pills gets tiresome) there’s
    NOW Supplements, Liquid D-3 & MK-7 with 2,500 IU Vitamin D-3 & 100 mcg Vitamin K-2 per 5 drops

    [another vendor, Protocol for Life Balance, offers an identical product at slightly higher price in Fullscript (if you’re a Masterpass subscriber)]

    Taking 5 drops of that plus a drop of the Thorne D/K2 (with MK-4) provides 200 mcg of K2/day + 3,000 IU of D3, which should be perfect for my needs and provides half of the K2 as MK-4 and half as MK-7.

    1. none of the products in those links contain BOTH mk7 and Mk4.

      I would suggest vK2, which contains pharmaceutical grade MK4 (5mg) and MK7 (100mcg).

    2. Margaret, I apologise for my seemingly late reply to this post of yours, as it was from Feb, 2021, and just appeared in my mailbox, being now Sept. 2021.

      You wrote “I’m getting those for my mom, who seems to have a severe K2 deficiency at present since taking calcium is apparently giving her hypercalcemia where she can’t keep her balance when walking. ” referring to a form/product of k2 in that post. Since I don’t know the actual context for your comment, please forgive me if I’ve missed any details previously or consequently presented about your mother.

      FIrst, if I were you, I’d ask, (not a doctor or even as medical professional), has your mother’s hypercalcemia been documented as consistently over a level of 10 mg/dl for serum blood calcium, assuming that she is at least 40 years old? If this is the case, then I’d recommend looking at websites about hyperparathryoidism. parathyroid dot com is comprehensive.

      Since excess vitamin d has been known to boost calcium levels too high in some people (perhaps vitamin k2 deficient, but not necessarily!), you’d want to rule that out also (vitamin d being known to enhance absorption of calcium from our guts) as a possibility. I’d carefully the assumption that her problem is a deficiency of vitamin k2 (although a deficiency might be true, esp. if much older and with some issues in converting vitamin k1 into vitamin k2, as is probably more common than accepted due to high levels of potential environmental complicators such as glyphosates that are difficult if not impossible to measure in our bodies and our food and water, and yet might have a detrimental impact on the necessary bacteria in our bodies, and other nutritional factors that could interfere with that conversion).

      If the usage of vitamin k2 has reversed your mothers hypercalcemia, please let us know.

  34. I make sourdough bread and natto at home but my kids won’t touch the the natto. Might it be possible to mix some natto into the dough, let it ferment/prove and the bacteria replicate (usually I prove for 8-12h) and then bake it? Would the K2 be destroyed by baking?

  35. also it’s “YoungGlo Research” not “Young Life Research” and while those are the cheapest per mcg of MK-7 when bought in 4-packs and the other brands aren’t on sale, I don’t like that it comes in a translucent blue bottle, when because K2 is very light-sensitive it should be packaged in an amber or opaque bottle.

    1. I am pretty confused. In your opinion what brands of K2 have the best balance? I am most concerned with quality and taking the right balance of MK4 & Mk 7. I especially take it for my bones. I was taking the Synergy K, but now I will stop after you explained why it is not a good balance and that K1 is not suggested. I truly appreciate your help.

      1. Aside from vK2 containing an optimal amount of both MK4 and Mk7, it is also pharmaceutical grade, characterized by its yellow color. Unlike most other vitamin K2 products, the ingredients for vK2 are NOT sourced from China (they come from Europe).

      2. Janel, please search for the section above titled “The Three Best Vitamin K2 Supplements”. At the bottom of that section you’ll see a green outline button thingy with lighter green print “Click here for a comprehensive review of supplements” [I wish that Chris would make these solid color with white lettering, so that these are easier to see/read and harder to miss].

        That section will expand to show a bunch of additional text. Read what Chris has to say about the Life Extension Vitamin K supplement in that expanded section and too much K possibly overtaxing the antioxidant system.

        Also look at the section titled “Hypothetical Side Effects of High Doses” and read the expansion/detailed explanation for that. Then you will understand.

        The Synergy supplement might be good for someone who won’t eat many green and yellow vegetables and doesn’t get much vitamin K1. That’s probably not you. I logged all the foods I eat into the daily diary in the Cronometer app, and discovered that on average, I get more than enough K1 from my diet (the app doesn’t break it down between the two types of K, but I know that generally speaking except for natto the plant foods are providing K1 and the animal foods are providing K2). I do eat natto, but getting the organic natto is expensive and I don’t eat enough animal food (and am on a diet that restricts dairy for the time being), hence I’ve chosen to get much of my K2 from supplements and will plan to continue to supplement MK-7 even after I hopefully can resume eating dairy.

        Unless you have some kind of identified genetic dysfunction that you have to compensate for, generally speaking, everything in moderation, eat a wide variety of foods, not overdoing any one thing is best and safest.

        1. Thank you. Do you like any particular brand of K2? I do have to avoid some veggies, due to oxalate issues. I do eat Brocolli & Cauliflower but that is about it in veggies. Your opinion is appreciated and your help in understanding how to navigate the info here is extremely helpful.

          1. See my comment posted down a ways earlier on this topic. After I posted that I also saw that some other companies make MK-7 capsules sold on Amazon. You want to look for one that says it consists of the product made by Menaq7. Anyway, since Chris recommends 200 mcg total of K2 per day, and a mix of MK-4 and MK-7 as they seem to act somewhat differently in the body (though some people seem to be sensitive to MK-7 for some unknown reason), I’m supplementing with 100 mcg of each and that should be good enough. There are also supplements with 180 mcg of MK-7 as well that claim that 180 mcg is what’s been studied to work well.

            There are cooking techniques you can use to reduce oxalates in veggies. For example, in traditional Japanese cooking some green veggies are parboiled in salted water and the water is then drained. You can search online to research how much that helps for things like spinach etc. It helps a lot with taro.

            I recommend you track your food intake for at least 3 days in the Cronometer app, to get a sense of how much K1 you get through diet. But if you don’t have any issues with blood not clotting well you may be fine as well as K1 is concerned.

            The ultimate proof is how your next bone density test comes out (while keeping in mind that K2 is just one factor in increasing bone density).

  36. I am guessing that future studies will find that the MK-10 and MK-11 in pork does get converted to the other forms, because the long-lived Ogimi people in Okinawa eat moderate amounts of pork, but it doesn’t look like they eat much natto.

    1. There is a lot of speculation regarding optimal K2 dosage. Obviously more studies are needed. However, I think its safe to say that Mk4 and MK7 are NOT dose equivalent. I do not consider it reasonable to split the numeric value of a recommended dose of mk7 into MK4 and MK7 components to that value. They are NOT dose equivalent. Their respective doses differ by an order of magnitude. MK7 dosage are generally expressed in mcg’s, while MK4 dosages are generally expressed in mg’s.

  37. It seems that the Nested Naturals K2 product is discontinued, and now they only offer a K2 product that is combined with 5,000 IU vitamin D unfortunately.

      1. thanks but that one looks way too imbalanced. Way too much MK4 (1 mg) and not enough MK7 (45 mcg), plus it has a lot of K1 which I get plenty of from my diet, and Chris Masterjohn cautioned getting unnecessarily high amounts of Vitamin K may be harmful.

      2. thanks Jan but that one looks way too imbalanced. Way too much MK4 (1 mg) and not enough MK7 (45 mcg), plus it has a lot of K1 which I get plenty of from my diet, and Chris Masterjohn cautioned getting unnecessarily high amounts of Vitamin K may be harmful.

        1. I had good results in reducing artery calcification with the similar Vitacost advanced K complex with 1.3 mg of MK4 vitamin K2. That is actually a small amount, optimal doses for MK4 in research run up to 45 mg per day. I’ve seen research with lower doses of 5 mg to 15 mg daily giving good results with bone or artery health improvements.
          The use of MK4 is safe because the body discards what it doesn’t need, so doses up to 135 mg per day have shown little in side effects. In youth the body makes enough MK4 from vitamin K that supplements are not needed.
          The MK7 is generally used in much smaller amounts. It is made by bacteria so is not a natural part of body chemistry like MK4 is.

          1. I just had a coronary calcium San with score of 60. Previous ones had been 302 and 319! I’ve been taking 30mg the last two years of relentless bit k2-4. Is that really possible ??I don’t understand how it went down that much. Happy if it’s right.

      3. what I settled on was one drop of Thorne K/D2 and one tablet of Source Naturals Vitamin K2+D3, plus one drop of Now Extra Strength Liquid Vitamin D-3 to get sufficient D3 as needed. This gets me 100 mcg of MK4 and 100 mcg MK7 each day. I see that the Doctor’s Best, Natural Vitamin K2 MK-7 with MenaQ7 is a slightly better buy for MK7, as is the Sonora Nutrition Vitamin K2 that Chris lists in the expanded Comprehensive Review section.

        1. though at this very moment iHerb seems to be having a sale on the Source Naturals so that it is actually cheaper at present than the Doctor’s Best

  38. I tried to read through the whole post but it’s quite long. Is there a suitable Vegan MK-4 / MK – 7 supplement please? I am kind of overwhelmed with choice and opinions and have no way of measuring validity. Thank you so much.

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  40. k2 180 mcg, together with d3 5000 iu ,together with angstrom ionized magnesium ,or magnesium malate/glycinater 800-1600 mg,

  41. I’m reading that D3 and K2 should not be taken at the same time. Have you researched this issue? Conclusions?

    1. Where did you read that Bonnie? I’ve never seen that anywhere and given the different actions of D3 and K2 I can’t see why it would be a problem. I think that’s probably one of the myths that float around the internet such as “don’t shower after sun exposure ‘cos you’ll wash off the Vitamin D”.

    2. Bonnie . . . Where did you read vitamins D3 and K2 should NOT be taken at the same time? I’ve never seen any studies that suggest that. Quite to the contrary, they SHOULD be taken together. Vitamin D stimulates the production of gla proteins, which do not do anything, unless activated by vitamin K2. In fact, as the dose of vitamin D3 is increased, the demand for Vitamin K2 increases proportionally.

      1. Hi. I have read the SAME. Not that D3 should not be taken, it definitely should, but to not take it at the same time as the K2. I believe I read it in a book called REBUILD YOUR BONES, The 12-week Osteoporosis Protocol by Mira and Jayson Calton, PHD. I, too, would love more insight into the issue.

      2. I’ve also read the same….NOT to take D3 at same time as K2, though one should be taking both of them…just not at same time. I think I read that in a book by Mira and Jason Calton, PHD. Book is Rebuild Your Bones, the 12-week Osteoporosis protocol.

        1. Dicksie . . . I have not read “Rebuild Your Bones”, but i did look it up on amazon, and the preview and/or table of contents makes no mention of thesis you have asserted. I have also searched the authors in pubmed, but came up empty. They have not published any clinical trials on this topic. I am not going to say authoritatively that this thesis is wrong, but Ive not seen anything to make me believe it. I can not imagine, what the rational might be, considering a) vitamin D3 needs to go through 2 hydroxylations before it becomes active and b) vitamin K2 does not interfere with those processes, which take care in the liver and kidneys respectively c) Vitamin K2 has a relatively short half life. So If not taken at the same time how else would they able to work in tandem. If you find any studies to substantiate this thesis, I would be very interested to know of it, but as I already said, I’ve never seen any such studies

          1. Thanks, Eric! I have not read it elsewhere, either, but did see it in that book…I think that is where, anyhow. I will dig the book out and see if, indeed, that is the case. I, too, TRIED to search farther on it, but found nothing. Appreciate your input. Apparently Bonnie must have also read it somewhere….though that does not make it ‘so’ just because someone (though he is a doctor if it is from that book) is stating it. Sorry about my double post. I could not tell the first one went through 🙂 It absolutely is a ‘pain’ to TRY to take them separately since I take supplements both morning and night…. Appreciate your response.

          2. Yes, the Calton’s are promoting this concept. They suggest that both K2 and D3 are competing for the same receptor sites, so they should be taken separately over the course of the day. Happy to see it disproven, but I see this idea popping up all over the place online.

          3. See the webpage for the reference #16
            which brings you to the following:

            Fat-soluble vitamin intestinal absorption: absorption sites in the intestine and interactions for absorption.

            The interactions occurring at the intestinal level between the fat-soluble vitamins A, D, E and K (FSVs) are poorly documented. We first determined each FSV absorption profile along the duodenal–colonic axis of mouse intestine to clarify their respective absorption sites. We then investigated the interactions between FSVs during their uptake by Caco-2 cells. Our data show that vitamin A was mostly absorbed in the mouse proximal intestine, while vitamin D was absorbed in the median intestine, and vitamin E and K in the distal intestine. Significant competitive interactions for uptake were then elucidated among vitamin D, E and K, supporting the hypothesis of common absorption pathways. Vitamin A also significantly decreased the uptake of the other FSVs but, conversely, its uptake was not impaired by vitamins D and K and even promoted by vitamin E. These results should be taken into account, especially for supplement formulation, to optimise FSV absorption.

            Unfortunately, the full article is available online at ScienceDirect only if you have some sort of institutional access. Perhaps it is for sale too, and I’ve missed the link.

        2. I am taking 50mcg of Vit D3 every other day, and a daily dose of 200 mcg of K2-7 to avoid my blood pressure to go up. It seems that Vit D3 accumulates over time and affects my blood preassure. Also, eat some almonds along with Vit D3 for magnesium.
          When my K2-7 and Vit D3 are “balanced” I do not need to take my blood pressure medicine. That is my challenge on how to keep this balance. Any Comments or suggestions?

          1. Bonnie . . . What receptor sites are they referring to? The receptor sites for vitamin K2 are on the gla proteins (VKDPs) themselves. That is where they the VKDP activation takes place. Vitamin D3 is involved in production of these gla proteins and as far as i know, this production is not at all hampered by vitamin k2. Furthermore, vitamin D3 is hydroxylated (to become the biologically active form of vitamin D) in the liver and kidney. I am unfamiliar with any research that suggests vitamin K2 competes with vitamin D3 for receptor sites in the liver and kidney.
            In other words vitamin D and vitamin K do not have common receptors, so they do not compete for receptors. If you find any info that refutes my point, please share it. I could be wrong, but i do not think I am

    3. Let us look at this logically. Vitamin K2 and Vitamin D3 are both fat soluble vitamins found together along with Preformed Vitamin A as well as minerals like magnesium and calcium in healthy animal fats that have sustained the healthy bodies of traditional cultures for generation upon generation.

      Butter, lard, tallow, cream, cheese ghee all have K2 and D3 together. If one consumes too much fat soluble vitamins the body stores them in the body fat for use later.

      Conclusion: Logical Retroductive Reasoning shows that there are no issues taking D3 and K2 together.

      If one consumes too much fat soluble vitamins the body stores them in the body fat for use later.

      1. I don’t have a clue what retroductive reasoning is, logical or otherwise, but you 2 sound like you know what you’re talking about.

        All I can say is that the product in question, nutreince, has a miniscule amount of K: 40mcg each of V1, 4, & 7. I’m not qualified in anything, but based on everything else I’m reading, that sounds just about meaningless to me, whatever other qualities the product might have.

      2. Can I take Vit D3, K2 with Vit A? Do I need to take Magnesium the same time as D3 and K2? Can I use Magnesium L-Theronate?

    4. It is the other way around. They should be taken together which is why some supplement of D3 are combine with K2

    1. Jarrow’s K-Right contains Mk4 and MK7, but only contains 1500 mcg MK4 (not nearly enough). It also has vitamin K1, but it is not needed so I’m not sure why its included.

      Vk2® which contains 100 mcg (.1 mg) of Mk7 and 5,000 mcg (5 mg) of MK4. Most importantly both are pharmaceutical grade (with the characteristic yellow color) and sourced from Europe. If the brand of Vitamin K2 you take is white, then it is not pharmaceutical grade and is likely sourced from China.

  42. Obrigado!
    Aprecio muito a generosidade e frontalidade.
    Especialmente em tempos de Covid, os teus escritos são uma luz abençoada para muita gente atónita que se desviou do equilíbrio da natureza. Eles estão aterrados com as comorbidades, mas sem o saber, vão destruindo a ‘tua’ vitamina K.
    Como eu te entendo! Obrigado.

  43. Hi Chris–Can’t thank you enough for your exhaustive and trustworthy research. You’ve been an invaluable resource! I was diagnosed a couple years ago with histamine intolerance (history of migraines, hives, rashes, other symptoms). LOTS of research and staying as low-histamine as possible with diet, meds (no NSAIDS, for example), has helped. I’ve been taking K2MK-4 daily to address healthy calcium absorption, but have avoided MK-7 because it’s from fermented sources. Fermented foods are a known histamine trigger. So does that make K2MK-7 supplements off limits? If so, what to do? It’s a very important vitamin.

  44. So, question: I have a hereditary clotting disorder, “heterozygous prothrombin G20210A” if you know what that means, which gives me slightly higher risk for abnormal clotting.

    Is K2 of any description safe to take with this? I already take D3 along with magnesium and would like to add K2 but am afraid of causing arterial or venous thrombosis/thromboembolism. I’ve already had one PE with apparently no precipitating DVT, and do not want to go through that again.

    1. Melodei, tri-k has vitamin K1 (which you do not need) it does have some vitamin k2 (MK4) but only a small amount (500 mcg, which is .5mg). It has no MK7 at all. Its very expensive too. vK2 contains both MK4 (5 mg, which is 10x more than what tri-k contains) and MK7 (100 mcg)

  45. I wish you could replace or add measurement symbols that are used in the United States so I could better understand it in context of your information. I am retired and have hard enough time when I read it the U.S. weight symbols. Thank You

  46. Has anyone has taken vitamin K2-7 along with garlic that could share his experience? Also what is the optimal doses for K2-7 to unclog arteries?

  47. I started taking K2 (Carlson MK-4 5mg/day) about 3 weeks ago, along with magnesium glycinate (360 mg/day — broken up 3x/day), vitamin D3 (2000 iu) and also I will take some of the fermented cod liver oil/butter oil mixture (maybe 2-3 capsules a day).

    I was having trouble with my teeth chipping or developing white spots; this still seems to be going on (I notice new chips or spots everyday). I even had some gum bleeding when flossing (I’m a regular flosser and that hasn’t happened in years!) I’m not sure of course if those problems would have developed anyway. Could I be doing more harm than good? Maybe it’s too much K2?

    By the way, for diet, I do eat milk and yogurt, also cheese (I even focus on Jarlsberg, Muenster and Gouda to try to get the MK-7). It’s possible it’s still not enough calcium compared to the supplements though.

    1. I’m no expert on nuthin’, but . . . I don’t think 5 mg is too much. I’ve been taking 25 mg/day for about 2 1/2 months, and nothing bad has happened. Also, I’m not sure 3 weeks is long enough for anything bad to happen, although in a world of uncertainty I guess just about anything is possible. Have you asked your dentist what could cause your symptoms?

      1. I did ask, the best thing we could come up with was I was grinding my teeth and chewing on my nightguard, putting pressure on the teeth. I’m going to get Invisalign to fix the bite and help with the grinding.
        I had my blood levels checked as well, calcium is okay (9.7 mg/dL), vitamin D is borderline low (29.3 ng/ml). I think I need to raise my vitamin D a little and if I’m taking vitamin D, then I need to also continue with K2. Hopefully that helps with my teeth issues over time, since I’ve heard so many anecdotes about how much it helps.

        1. Again, I’m no expert . . . but I don’t think 29.3 is borderline–it’s low. I read some supplement seller’s comment once that a good target range is 50-80, so I wouldn’t be shy about getting it up. And you said ‘D;’ I assume you mean D3.

          1. Chris has written before that levels maybe should be more like 30-35, and that it could also depend on your race.

            Of course, these things are all in balance with each other. I feel like I’m still trying to figure out a good balance of K2, D, and A with each other. I hope to find it soon, and also to experience some of the improved health benefits that other people have seen.

          2. I’ve continued on with the K2 as well as the other supplements. I also added some occasional vitamin C hoping to deal with the gums. It’s been nearly two months now.
            Yet I noticed another white spot on one of my teeth and there even seemed to be some brown next to it.

            I don’t know if I’m just noticing things that were already there from before, or if new problems are really cropping up. I even contemplated that the spots were a sign of healing — maybe my teeth are changing color as they absorb minerals. Then I notice it because it changed.

            I feel like the only thing to do is to continue with the protocol, which seems pretty balanced in terms of getting all the fat soluble vitamins. Diet-wise it seems pretty good, with yogurt and beef liver and a variety of vegetables, and I’ve been getting more sun.

            It might be the case that it just needs a good 6 months before the positive changes become noticeable. I don’t know because a lot of people reported whiter teeth and no tartar after only a week or two, but so far I haven’t seen this happen.

          3. Abby, I’m replying to your comment of 7-16 below my comment since there’s no ‘Reply’ option below your comment. (But it’s looking like this comment might end up in the right place anyway.)

            It’s not clear from your initial comment if your teeth problem began before or after you started taking K2. If you stop taking K2 and the problem goes away, I guess that settles the issue.

            You might want to get an opinion from a second dentist. My dentist’s receptionist is pretty knowledgeable, so you might find a similar situation where you don’t even have to visit the 2nd dentist.

            Good luck since nobody here seems to be able to be real helpful.

          4. Not sure where the reply will go 🙂
            I had teeth problems before– I chipped a tooth back in January and noticed a decalcified spot. I started to try to fix these issues in March but didn’t learn about K2 until May. I did start on cod liver oil in March though.
            I also started feeling like my bite was bad, and that I kept tapping my teeth against each other when eating or talking. I felt extremely uncomfortable and a sense of something being wrong.

            Anyway, I thought taking K2 would help me with these issues. I started examining my teeth more thoroughly with a flashlight after I started taking the K2. I noticed a white spot a few days after I started. Then a few days after that I noticed some chips. Now a few weeks later I notice the new white/brown spot.

            I was hurting before, which is why I started the K2 in the first place, so it’s possible these problems were already there/already in development and only noticed by me later. It’s impossible to say.

            It does seem like maybe I should pause the large dose K2, and only take what I get from my cod liver oil/butter oil mixture and also from food. I think part of the reason I haven’t stopped yet is because I was concerned about vitamin D3 — but since my levels are still low, perhaps it is okay to pause for a few weeks, anyway.

            Thanks for your help vanp, I think it is just a confusing problem. I have an appointment on Monday (regular doctor, not dentist) so I might ask then as well

          5. You should ask the doctor, of course, but don’t be surprised if he don’t know squat about any of this. I’ve been taking Green Pasture’s butter oil and cod liver oil pills for years with no problems.

        2. 29ng/ml is not “borderline low” regardless of what your doctor or dentist tells you, it is VERY low. This is just another example of where mainstream medicine has set the bar for vitamins and minerals way too low. I suggest you look at this blog post by the late Dr Robert Heaney, one of the foremost researchers on Vit D and osteoporosis:

          When your body is not getting enough calcium from the diet it needs to increase the supply NOW or you die. Consequently a signal is sent to the parathyroid gland to increase the release of parathyroid hormone (PTH) to break down bone (and presumably teeth) to provide the calcium necessary. Chronic Ca deficiency and elevated PTH causes osteoporosis. I’d think it’d also weaken your teeth. In order to absorb Ca from your diet you need adequate Vit D.

          Look at the graph of PTH vs 25(OH)D (the active form of D). Each circle is an individual patient’s result and the red line is a mathematically calculated “line of best fit” to the data. The point where the line flattens indicates where on average a further increase in D levels does not provide further benefit in terms of PTH and bone loss, though obviously there is a lot of individual variation. Dr Heaney writes:

          “The figure shows clearly the expected high levels of PTH at low vitamin D status values, with PTH concentration falling and becoming essentially flat as vitamin D status rises to levels in the range of 125 nmol/L (50 ng/mL). Exactly the same relationship is exhibited in a report from the National Health and Nutrition Examination Survey, involving a population-based sample of over 14,000 individuals. Both data sets found almost exactly the same vitamin D status level, above which PTH fell no further.

          Because there are many factors that influence PTH concentration beyond vitamin D status, this approach will not work very well in determining individual requirements of calcium or vitamin D. However, it does work at a population level, as the graph shows. The point at which further increases in vitamin D status produce no further decreases in PTH concentration [i.e., a plot of PTH on 25(OH)D is flat] defines the PTH set point for both calcium and vitamin D. This is the point around which the body can exercise its regulatory control of serum calcium concentration with optimal capacity in both directions. The need to compensate, and the duration of adaptation are minimized. Such a value would seem to be a reasonable estimate of optimal vitamin D status, and therefore an indicator of the vitamin D requirement.” Dr Heaney’s average optimal D level of 50ng/ml compares with Dr William Davis’s recommendation of 60ng/ml for heart health.

          To ensure adequate health of your bones and teeth you need:
          1) a calcium-rich diet
          2) enough vit D to absorb that calcium
          3) vit K2 to direct Ca to bones and teeth
          4) weight bearing exercise to build bone
          It sounds like you have 1 and 3 covered but possibly are not getting enough D.
          Check that your results actually are in ng/ml and not nmol/L – 29nmol/L is severe deficiency- and that they are measuring 25(OH)D the active form. Your level of 29ng/ml equates to about 75nmol/L. As you can see from the graph 75nmol could be either high or low depending on the individual. Get a PTH test to determine your levels. A bone density scan will determine whether you have a degree of osteoporosis. If so DO NOT allow your doctor to prescribe bisphosphonates (eg Fosamax or another brand name). These drugs show better scan results but don’t reduce fractures. Instead, make sure your C, D, K2, magnesium and protein levels are high and walk, run or skip rope. All of Dr Heaney’s blog posts are well worth reading.

          1. I want to make a correction to Stuart’s post.

            25(OH)D is NOT the active form of vitamin D3.

            Actually it is 1,25(OH)D which is the active form

            25(OH)D (calcidiol) is however, used to measure vitamin D status, even though 1,25(OH)D (calcitriol) is the active form.

          2. I think it’s important to remember that your optimal level of vitamin D3 intake depends on your vitamin K2 status because if that is insufficient, high levels of vitamin D3 intake, which would otherwise be healthy and provide enhanced immune system function, are likely to cause abnormal calcifications in your arteries and other soft tissues.

        3. Yes, your D3 is too lower. I would double what you are taking and have your D3 tested again in three months. So if you are taking D3 1000 IU, I would take 2000 IU. I see wrote this in June so I hope your levels are tested again and then go from there.
          James Kantor, Raleigh, North Carolina.

    2. I posted a lengthy reply to this post several days ago and it still hasn’t appeared. System admin please check your Spam folder. Thanks

  48. Has anyone ever notice facial difference taking vitamin k2 mk4. I have read on forum peoples faces change from taking it. they notice are more prominent cheek and jaw development. This from megadosing it. Unfortunately no one ever post photos so its hard to tell if its true or not.

    1. I read that mk4 can affect jaw development in embryos and infants, so that the jaw actually accommodates all of our teeth. Wisdom teeth pulling would be unnecessary if we were given adequate amounts of mk4. EMU OIL for the win.

  49. Sure, Emma, Vegans are also deficient in Vitamin K. You will probably not feel any signs, even though the arterial linings and heart valves are likely to build up calcium. VK2 is shippable to Australia. I hope this knowledge will be of use to you

  50. Hey, what do you think about Pure Therapro?

    I want to start supplementing my 4 year old’s diet with K2, but can’t find any full spectrum except this one and the Innovix – not sure I can give him that because of dosage and difficulty swallowing. Not sure about the reputability of Pure Therpro but I was happy to see a full spectrum K2 in liquid format.

    I’d appreciate any insight at all 🙂


      1. Right, but vK2 is a capsule, which my 4 year old can’t down. So I just wasn’t sure if you had any opinions on the brand, Pure Therapro! Thanks!

    1. I’m no expert on this stuff, but the MK-4 dosage is miniscule–probably not worth taking. Also, I may have missed it, but it doesn’t seem to say “no soy.” Not sure how big a deal this is.

    2. Like Vanp suggested, the amount of MK4 contained in that product is so small as to be useless. It also contains Vitamin K1, which most people do not need at all

    1. Shalom,

      NHS Global Distributors, Inc sells 2 products that may be of interest to you.

      vK2 contains 5mg of MK4 and 100mcg of MK7 (both are pharmaceutical grade)

      Dmax contains 5,000 iu of Vitamin D3

    1. Their website does not provide much info. I see that it contains both MK4 and MK7 but only 100mcg of MK4, which is a tiny amount. (Our Vk2 product contains 100 MG of MK4)
      I also see that it contains magnesium stearate, which I consider a substance to avoid

        1. Yes, Vamp . . . my Bad . . .The MK4 amount in Vk2 is 5 mg of MK-4 (not 100 mg as previously posted). I’m so sorry for the mistake. It’s also worth noting that it is pharmaceutical grade (unlike the ingredients of most others Vitamin K2 products).

      1. I see MK 4 at some very high doses, do you know who has it a a lower dose more like 500 mcg or 1000 mcg, which is SOY Free ( Menaquionine) and also has MK-7 in it?

        1. Innovix Labs ( Full Spectrum Vitamin K2’s MK-4 is 500 mcg, MK-7 is 100 mcg, no soy. Eric’s vk2 product above is 5 mg of MK-4 according to the website, not 100 mg.

          1. Yes, my Bad . . .The MK4 amount in Vk2 is 5 mg of MK-4 (not 100 mg as previously posted). I’m so sorry for the mistake. It’s also worth noting that it is pharmaceutical grade (unlike the ingredients of most others Vitamin K2 products).

    2. Overpriced at $35 for 60 capsules and the doses are minuscule. I can buy 30x180mcg of MK-7 at retail for $AUS15 = $US10 ie roughly the same dose of K2 for one-third the price. iHerb will sell you 250x100mcg of MK-4 for $US17.27.

      Another comparison is with Koncentrated K
      This is $45 for 60 capsules each containing 30.5 mg of K – 25 mg of MK-4, 0.5 mg of MK-7, 5 mg of K1 and 2 mg of Astaxanthin.

      If you’re trying to reverse atherosclerosis or osteoporosis IMO you need to be taking K in milligram doses not micrograms (200mcg = 0.2mg). In Japan they give 45mg/day of MK-4 to treat osteoporosis. I’d buy Koncentrated K.

      Re the natural vs synthetic issue AFAIK all MK-4 supplements are synthetic whereas MK-7 is almost always extracted from natto. I don’t see either as an issue unless you are allergic to the soya in natto.

      I presume “GundryMD” is the vegan quack Steven Gundry. He’s basically having a contract manufacturer make it up for him and slapping on his label and a hefty markup. None of the brands you see for sale make the active ingredients – they buy them in bulk and package them in pills or capsules. For any given active ingredient there are a handful of original manufacturers (sometimes only 1) that supply all the retail brands. So one brand’s MK-4 probably came from the same source as another’s. Buy based on dosage and price.

      1. I agree with most of what Stuart’s post, but disagree with his assertion that “one brand’s MK-4 probably came from the same source as another’s. Buy based on dosage and price.”

        Most are sourced from China. Both the MK4 and MK7 contained in Vk2 are European sourced and have a yellow color characteristic of pharmaceutical grade, as opposed to the white Chinese materials, which are certainly NOT pharmaceutical grade.

      2. I had estrogen receptor positive breast cancer and will not take anything that includes soy.

        I am not trying to reverse osteoporosis or atherosclerosis. I just want a good non GMO soy free low dose K-2 supplement.

        Thank you SOOOOO much for taking the time to share your expertise.

      3. Stuart, You mention that Japan uses 45 mg per day of MK-4 for reversal of osteoporosis. I actually read that study…or a couple of them…a couple years ago, but have been unable to locate it online to review it again. I had ‘thought’ that in the study they actually used 45 mg given 3x per day! Would love to know which it was…45 mg. total, or x3. Maybe it was 15 mg x 3? Thanks so much.

  51. Awesome article. Very informative. Is there any well researched article or studies confirming amounts of k2 is high vitamin butter oil the type recommended by weston price to augment benefits of cod liver oil and provide k2? Would you consider vit oil like this a real source of vit k2? Ty. Jennifer Corgan

    1. I was diagnosed through a CT scan with heavy atherosclerosis. I’m wondering if vitamin K can reverse the arterial plaques? Also, my brand of supplement is in milligrams so I don’t know if it falls into line with your recommendation. Here is the breakdown:
      MK7 = 100 mg
      MK4 = 1,300 mg
      MK1 = 1,000 mg
      These are in a base of MCT and rosemary oil. Is one a day adequate? I take it with 5,000 it of vitaminD and also with fish oil supplement. The only prescription meds I take are 2 blood pressure meds and Metformin. Thank you for access to this wonderful resource!

      1. The reversal would need two things, a reduction in insulin levels by any means and the addition of the MK4 vitamin K2 along with 5000 IU vitamins D3 and A to the diet.
        The first would be done by getting carbs under 50 mg a day, avoiding fast or starchy carbohydrates, taking 50 mg of Niacin with each meal, then increasing it about every two weeks, taking a 500 mcg chromium supplement. These will all reduce triglycerides.
        Second, take an MK4 supplement of 1 to 15 mg, higher if the condition is serious. The vitamins D3 and A will make the calcium removal in arteries more effective.

        Beyond this coenzyme Q10 and alpha lipoic acid are popular cardiac health supplements. You might look up NO More Heart Disease by Dr Louis Ignarro who tells hoe nitric oxide protects the arteries from heart disease.

        I used the Ultra K supplement with 1.3 mg of MK4 and was startled when over 12 months it got rid of artery calcification and the symptoms I’d had for twenty years. Good luck.

    2. Tumeric, found a video on u tube from a woman in Hawaii who said something about there being more than one pathway to absorption of nutrients. News to me. Dr berg probably has videos there on that subject, possibly supplements too.

  52. Hi! I have CAD (plaque in my arteries) and osteoporosis. I think I need K2, MK4 and MK7! I also have one positive and one negative for Factor V Leiden and recently began Eliquis. What kind of doctor would manage my supplementing with Vit k? Is K2 involved with clotting or just or more so K1? I really think K is the answer but need guidance. I would appreciate your advice! Thank you!

    1. Are there any research articles addressing the effect of vitamin K2 in the treatment of kidney stone?

      I have been taking K2D3 at the recommendation of my naturopath. My nephrologist is looking for clinical studies.
      Any recommendation?

      Thank You!

  53. Comments needed on Koncentrated-K from P. Theut. Is this the best therapeutical dose product going? Any success stories with valve calcification? I have it, ready to give to mom. Please, thank you. Daniel

  54. Please add Greek Yogurt to you data. A common one I use is Fage, whole or 2%. Now I am beginning to see why whole fat is better, I would guess K2 , D3, and A vitamins would be higher.
    You say take 30+ grams of fat with K2 MK7 , a tablespoon of oils less than 15 gram. Can you share your thoughts.
    Thank you for answering and for the time it took to write this article, and database. I hope you will do more YouTube on K2 and diabetes and cardiovascular health.
    James Kantor, Raleigh, North Carolina

  55. I am a vegan with low bone density. I would like to eat Natto (only available near me in the frozen form) . My question: Does freezing reduce the Vitamin K2 content?

    1. I have Natto in powder form, and I am wondering about the K2 in that. Unfortunately the bottle doesn’t say. I bought it from Amazon.

  56. My name is Jeff Mindrup. I am working on a db to track CAC regression strategies and openly publish the data to all who want it.

    I am on Twitter as MexicoBluePaleoKetoGuy @jeffmindrup

    Today, I found some interesting research that shows bioavailability of MK7 is significantly enhanced by taking MY7 with EVOO (~ 4 tsp or 12.5 grams)
    By doing so, under carboxolation of osteocalcin is decreased and carboxolation increased. By proxy, it is safe to assume the same for matrix GLA protein.

    This means the standard regression of ~ 50% per 18 months can be easily sped up and made more affordable.

    I highly recommend Saint Patrick’s Kon K, reading Kate’s book and ratios of A and D3 to MK7 and now the addition of EVOO when taking.

    I also rec eating frozen chunks of natto daily if you have a high CAC score. It is by far the best source of MKn’s (all of them) as well as fibrin breaking nattokinase. See Malcolm Kendrick’s tree ring explanation with Ivor Cummings.

    1. Hi Jeff, I am trying to understand what you are saying in your post. I truly do not know anything about Carboxolation. I have heard hundreds of seminars about K2, MK 7 & MK4, Vitamin D 3, Vitamin A, but never has this term been used. I know about Fibrin as well; due to my own blood work. What is MY 7? What is EVOO? What are the benefits? Are their any toxins in liquid EVOO? Where is it from (manufactured)? I never heard of a CAC score when doing any of my bloodwork. Thank you for clarifying.

      1. Hi Jan, I can’t answer all of your questions, but CAC is coronary artery calcium score…an indicator of plaque build-up in the arteries for those using K2 for arterial health. EVOO is Extra Virgin Olive Oil…it can actually be a ‘grade’ or designation given to olive oil to indicate the quality of said oil. As I recall, the author of Vitamin K2 and the Calcium Paradox gets into the deffinition and explanation of carboxolation…I don’t recall enough of the details to explain. Lastly, I’m ‘guessing’ that when Jeff said MY-7, it was a typo and he meant MK-7. Hope this helps. I found his comments fascinating and will do more research 🙂

        1. Yes – apologies for any typos. EVOO = olive oil. See study for more info but this is critical because bio-availability and absorption are significantly increased. We also know that not all fats are the same from another study comparing corn oil and EVOO w/sunflower oil. Again the EVOO, despite being a blend was superior for carboxolation.

          Jan, I’d really like to speak with you as well as get your help in getting your following to input into the db I am building which will be focused on CAC regression strategies.

          The end goal is to freely distribute the best practices for CAC regression and improve upon what appears to be the standard (for APOe3/3s anyway) of about 50% every 18 months.

          Kind regards,

          @jeffmindrup on Twitter

          1. Looks guys. There are some crazy uninformed and un-researched ideas in here and they are confusing the crap out of even me that spent last 6 months studying this subject. Bottom line.

            # 1. Get Patricks Kon K – best formula – full stop. Best value, strongest, etc. From looking at the label and using the value tool Carlsons is waste of money once you understand it’s all about the MK7. (Exo Mk4 does not show in serum, MK7 converts to MK4 in vivo) Alternatively/additionally eat natto. I do everyday.

            # 2. Read Kate’s book. Just buy it and read it. Don’t be cheap.

            # 3. Yes – A, D, and EVOO to get full benefit of K and especially MK7

            # 4. Don’t get lost in the weeds – way too many unknowns with K and will be for some time because it’s can’t be patented and there’s little research on it. New study expected any day now. (but not well formed IMHO)

            #5. K2 shows zero toxicity in every study ever conducted. Half-life of about 36 hours, peaks at 4-6. If Lance Armstrong has tingling fingers, it’s more than likely from the dozens of other illegal drugs he cheated with. The guy gave himself cancer and is an admitted fraud and liar. Why give a POS any credit? PS his LiveStrong was a grift to benefit him. Not to help others. Corrupt through and through. Do your research.

          2. Responding to Jeff’s points:
            #1. Agreed that Patrick Theut’s Koncentrated K is the best value per gm, but I base that on its MK-4 content. I don’t agree “it’s all about the MK-7”. The Rotterdam group maintain that MK-7 is best based on it having a longer persistence in the blood. I’ve never found that argument convincing. If the body prefers MK-7 why does it make MK-4 instead and why is MK-4 found in human breast milk? What does the body do with the MK-4 from your supplement? Chris answers that in the article above – the cells preferentially absorb the MK-4 so that it is rapidly depleted in the blood. That says to me that MK-4 is the optimal form, but I also take 180mcg of MK-7 as insurance.

            #2 I can’t find a copy of Kate’s book here in Australia and I would have to order it sight unseen from the US. International postage would more than double the cost. To illustrate, I recently bought an out-of-print book from a US bookseller. That $US30 book cost another $US30 in postage plus 10% import tax and the conversion to Australian dollars makes it $AUS100. That ain’t pocket change.

            #3. As Chris outlines here:
            the body also requires magnesium and zinc to manufacture those vitamin- dependent proteins as well as dietary fat to absorb the vitamins in the first place.

            #4. Got a reference to that forthcoming study so we can look out for it? Why don’t you regard it as well formed?

            #5. Agreed I wouldn’t put much credence in Lance Armstrong. His main nutritional supplement was Vitamin S – S as in steroids.

          3. Curious…. How important do you consider the role of resistance training to up-regulate osteoblastic flux to signal “hey… the bones need more calcium and phosphorus… can anyone spare any?”.

        2. Thank you so much. I will be going for my first Calcium Scan. Trying to keep the heart healthy; I was able to bring down my Fibrinogen due to a vitamin supplement. So I certainly know the benefits of supplementation. I am trying to figure out a good balance when taking 3000 iu of Vit D3, How much K2 & A should I take? Because I don’t take 5000 iu of D3, it is hard to calculate how much of the other vitamins to take when it appears everything is based on 5000 of Vit D3.

      2. Jeff said “its all about MK7” which demonstrates that is clearly in the MK7 camp. I have not seen any studies that confirm MK7 is converted to MK4 in an efficient way. What about for older people? Does the age related conversion inefficiency of K1 to K2 also apply to any MK7-MK4 conversion? I would certainly not be surprised if it did.

        Clearly more research needs to be conducted on this important topic before any conclussions can be drawn

        My intention is not to bash Jeff or the product he is promoting, Rather I would just suggest that MK4 has many important qualities that distinguish it from MK7 and since there is no harm in taking MK4, so why not take it?

        1. I’ve used both MK7 and MK4 products, (not concurrently) together with D, and A and EVOO as well as a compliment of other synergistic nutrients/foods. Natto is not on my plate, yet, but that’s primarily as I don’t eat breakfast and that’s how it seems to have been used traditionally, and secondarily because I had cardiac rhythmic irregularities that were simultaneous with MK7 supplementation (about 9 years ago) and that have never reoccurred since ceasing MK7. At 64 yo, I’ve not had a CaC done or any known problems with blood vessels or symptoms suggesting the need for such a scan, although I’ve been tempted to do so just to find out (not a big fan of CAT/CT scans unless warranted) . The rhythmic irregularities also corresponded with unrefined organic Coconut Oil usage so I can’t be definitive as to the actual cause of the symptoms (possibly glycerine related and with low RBC magnesium level possibly related to chronic mercury toxicity possibly made much worse by 40 yo amalgam being removed by a dentist that took no precautions for his patient (and I’ve had 13 others of similar age since removed with the best precautions and thankfully without any problems since)), but in any case, the avoidance of both CO and MK7 eliminated the problem (together with judicious supplementation of Magnesium, Taurine and Arginine.
          It’s possible that by my age (or earlier, say early 50’s, when I first experienced problems mentioned above) conversion of the K’s has decreased considerably, both from k1 to k2, and from MK7 to M4. Low serum levels of MK4 after supplementation might be indicative of the nutrient being effectively used (rather than excreted; not sure if ever measured); high levels of MK7 persisting for days in the serum might be indicative of a problem with utilization ( a half-life of 36 hrs!).

          Just saying tho: a lot of people have reported problems with taking MK7 besides me. I’ve never had any problems with MK4 and I’ve taken upwards of 15-30 mg daily, although I’ve settled back on about 5 mg daily for a while now.

      3. Carboxylation is the last st that turns calcitonin and Matrix GLA proteins into functional chemistry in the body. This is done by MK4 vitamin K2 and to a lesser extent by the MK7 form. Both of these are needed for calcium metabolism, calcitonin works to build new bone and Matrix GLA reverses calcification of the arteries.
        The body turns vitamin K into MK4 vitamin K2 for this purpose. With age or high cortisol levels, MK4 production declines and patients experience bone loss and artery calcification. A supplement of MK4 is then needed. Several trials from Japan show a 60% to 80% reduction in bone breakage rates for the elderly with 45 mg of MK4 daily.

        1. Yes, MK4 works for bones, but there are no studies that show a benefit for calcification of the arteries. Only MK-7 works to reduce arterial calcification, as shown in studies.

    2. I just corresponded with a physician overseas undergoing a study on 1000 micrograms of MK-7 to decalcify the aorta. He advised me to use 720+ micrograms MK7 daily. While I greatly appreciated his advice, I have to ask others what they think, because I have been giving my mom (with severe mitral valve stenosis) 10mg MK4 Carlson brand and 360 micrograms MK7 Utzy Naturals brand daily for 9 months. I just want to make sure we are doing the best thing for her. Please, if you have any input we would appreciate hearing from you. Thank you, Daniel

    3. Any thoughts on supplement versions? Trying to determine MenaQ7 vs. Menaquin Gold products. Any of these better than the other? Using Kon K now, I just don’t see a lot about it. Important to be giving mom something that is very effective with her heart issue. Thanks for input.

  57. I don’t know who wrote the K2 article. It is incomplete the way it is now. The author mentions the book, Vitamin K2 and the Calcium Paradox: How a Little-Known Vitamin Could Save Your Life, by Kate Rheaume-Bleue, but he or she apparently didn’t read it, because it is necessary for Vit A (retinol) and Vit D3 to be present for Vit K2 to do its job of keeping out of the arteries and other soft tissues, and to put it into bones and teeth. A paraphrased sub-title in the Calcium Paradox book is: Vit D, Vit K 2 and Vit A: Better Together.

    I encourage everyone to read the Calcium Paradox book.

    1. Albinka – agreed 100%

      Way too many miss the A-D-MK7 ratio and provide harmful advice that could lead to hypervitaminosis. I have found supporting research for Kate’s ratio and sent it directly to her.


      1. If a person is taking 3000 mg of D3, how much K MK-7, MK-4, Vitamin A should they be taking? Thank you for your help. I have severe dry eyes from Sjogrens so I can’t read allot of books & I have a limited ability on the computer as well. If you can help me it would be appreciated. Ty

        1. I am not an MD and have one concern, the regression of CAC scores via MK7. Please see an ophthalmologist. I do 2x a year.

          56 and 20/10 vision – no glasses required other than for reading very small print.

  58. Awesome article… I’m interested in increasing my k2 and was thinking about taking it in a tablet to increas my dose. But Im on xeljanz ( tofacitinib) to treat my ulcerative colitis and one of the side effects is it can increase cholesterol levels. So was wondering if you may now if I can take a supplement of K2 whilst I’m on xeljanz especially if xeljanz my affect my cholesterol.

  59. BIG question here, as everyone talks about calcification of arteries. Can we assume that K2 will ALSO improve calcified heart VALVES? Mom has severe mitral valve stenosis, started her on daily 5mg MK4 (Carlson brand) and 180 mcg MK7 (Utzy naturals). Mitral valve area started as severe (Area = 0.96 cm2) to now at moderate (1.12 cm2) six months later. I am thinking we want to increase the dosage (basically double it) as progress seems slow. Can anyone offer comments please thank you so much. Daniel

    1. It may take 12 to 18 months for fully reverse this although you should hve good progress by 6 months. The MK4 form will work for calcified valves as well.
      You might increase the dosage, but also consider including a vitamin D supplement and a retinol vitamin A supplement. Both of these contribute to calcium control. The vitamin D3 increases the supply of the Matrix GLA protein that prevents calcium in the arteries and the retinol vitamin A makes the Matrix GLA more effective and reduces the rate of kidney stones. Best of luck with this!

      1. David thanks. Gave Mom 5000 i u D3 for years without K2 which we think contributed to this problem. She is taking so many heart pills we are trying not to add more. terrible. We have doubled the k2 dosages and now blood pressure is coming down which I believe should be expected side effect?

      2. Folks you have been very helpful. Do you have any consensus on Koncentrated K capsules which contain 25mg of K2 MK4 and .5 mg of K2 Mk7? Looks great, Thinking of trying this out on Mom valve stenosis. I bought it just seeing if others have experience using it.
        Appreciate your thoughts.

        1. Dan, the man behind Koncentrated-K is Patrick Theut. Pat was diagnosed with extensive heart disease by the Mayo Clinic and was a patient of Dr William Davis of Wheat Belly fame. Pat reversed his heart disease with high doses of K2 and other supplements and a Low-Carb-High-Fat diet. Google his name and you’ll get lots of hits where he’s been interviewed. He also gave some talks to the Wausau Wellness Centre that you can find on YouTube.

          I don’t have any personal experience with Koncentrated-K as I’d just bought a large supply of Carlson MK-4 before I came aware of Pat’s product, but I will order it once I use up my Carlson stock. On a cost/mg of MK-4 basis Koncentrated-K is the most cost-effective way of getting a large dose that I can find.

    2. Daniel I’ve just found this site and was interested in your post as I have severe aortic stenosis and have been researching the use of vitamin k to help. Would be very interested to know what your mum is using and if it’s helping ? Thank you

  60. Hello!
    I have a A1298C mutation. I would like to take k2 but I am a bit worried about the rick of clotting. I take daily 75 mg aspirin to prevent and my blod tests are normal.
    I have been searching for info regarding k2 and blod clotting but I can only find people who take warfarin. Could you please tell me if it’s ok to take k2 and if so, how much?
    Thank you!

  61. Hi 🙂 thanks so much for this article. I am vegan and have recently learned that it is not uncommon for vegans to lack K2 (although I don’t know what symptoms I should be looking for, or tests that could be done to determine this)
    I have tried buying the three recommended K2 products but none deliver to Australia. Could you please recommend one that does?


    1. Often there are K2 dosage restrictions related to vitamin K that get applied to imports which are totally unrealistic. You may be able to order the Thorne liquid K2 which doesn’t come in a specific dose. iherb also supplies to a number of countries with import restrictions. See if you can find nearby discussion groups on the MK4 vitamin K2 and ask there about suppliers.

    2. Emma, the major problem with buying from the US is the extortionate postage charges by the United States Postal Service. They regard those of us who post internationally as a cash cow that they can milk without a political backlash. (so just like Australia Post then) To make it affordable you generally need to buy from someone like iHerb who’ve organised alternative shipping arrangements to bypass USPS.

      I’ve bought Carlson’s 5mg MK-4 from iHerb
      iHerb seems to charge Australian customers 12% more than US customers and then there’s 10% GST on top. OTOH they don’t charge freight if you order $US40 or more.

      I also take 180mcg MK-7. This brand which I buy at Chemist Warehouse
      The US products all seem to be 100mcg and work out more expensive on a per mcg basis.

      An interesting product is Patrick Theut’s Koncentrated K
      It’s expensive but offers a high dose of MK-4 and MK-7 at the lowest per-dose cost I’ve seen. Pat says he hasn’t made a profit on the product and I believe it. Pat is a small operator so has to use USPS. You need to buy 2 at a time to amortise the postage cost.

      1. BTW it’s well worth reading Pat’s “My Story” on the Koncentrated K website and watching some of his video talks and interviews. Ivor Cummins interviewed Pat for his Fat Emperor series and Pat gave some talks to the Wausau Wellness Center, all of which you can find on YouTube.

        Unless you are a regular consumer of natto, as a vegan you are almost certainly deficient in K2 since the principal sources of K2 are animal products or fermented foods like cheese. The human body has very little ability to convert K1 to K2. In regard to the consequences of Vitamin K2 deficiency they are principally osteoporosis and calcification of the arteries which are in effect two sides of the same coin. Your body needs K2 to make the hormone that deposits calcium in your bones and prevents the Ca being deposited in your soft tissues. To determine whether you have those conditions requires a bone density scan for osteoporosis and a Coronary Artery Calcification scan will indicate the degree of calcification of your soft tissues.

        If the bone density scan indicates osteoporosis your doctor will probably want to prescribe a bisphosphonate drug such as Fosamax. This will improve your bone density scores which will make the doctor happy but not prevent fractures because it results in brittle bone that can fracture in normal walking. It also has a nasty side effect known as Osteonecrosis of the Jaw whereby the bone in your jaw dies following dental work, causing disfigurement and requiring facial reconstruction surgery. So refuse to take it

        To recover from osteoporosis you need:
        1) Adequate levels of Vitamin D either from sun exposure or supplements, in the region of 50-60 Ng/ml. Get tested. You need Vitamin D to absorb the calcium from your diet
        2) Adequate calcium and phosphate in your diet, since bones are composed of calcium phosphate in a protein matrix. The best source of calcium phosphate is milk and dairy products (another strike against vegans)
        3) Vitamin K2 from diet and/or supplements. Because there isn’t an easy way to test Vit K2 status it’s prudent to take supplements
        4) You have to ensure adequate protein in your diet, 1.2 grams of more of protein per kg of body weight. Note that this is 50% more than the Recommended Daily Allowance of 0.8gm/kg, which tells you how much reliance you can place on the RDAs and the dietitians who regard them as holy writ.
        5) Last but certainly not least, you have to undergo load-bearing exercise to stress the bones and provoke bone deposition. Both bedridden patients and astronauts lose bone mass through lack of stress on the bones. The exercise can be walking or lifting weights or something as simple as skipping rope.

        For more on osteoporosis read the blog of Robert Heaney
        Until his recent death Heaney was probably the preeminent researcher into osteoporosis.

        I’ll write more about the implications of a CAC score later.

    3. Yes Emma, Vegans are often Vitamin K deficient. You would not likely notice any symptoms, even though you are likely building up calcium in your arterial linings and heart valves. VK2 can be shipped to Australia. I hope this info is helpful to you

    4. Hi Emma,
      Vegans will be deficient in vitamin K2, MK-4, because it is only found in animal foods. Too bad you couldn’t take advantage of the wonderful source of K2 -MK-4 -found in Australian emu oil, such as Emu Tracks, which is in a food matrix and well-absorbed by humans. MK-4 is the ONLY bio-active form of vitamin K2 for humans. We are not bacteria. However, there is much controversy about bioavailability and absorption of supplements in general, which are most often made in a lab and not from natural food substances, nor are they located in a food matrix as are nutrients in food. You may absorb a limited amount of MK-4 from an artificial supplement but who knows how much? I recommend a natural source which is much more bioavailable.

    5. I’m not sure why so many have complained about the cost of shipping to Australia. The cost of shipping 1 or 2 bottles of vK2 is $16.25 (First-Class Mail International)
      3 bottles ship for $25.50

    1. Yes, it is helpful for improving artery calcification and has been listed so by the Health Ministry of Japan since 1995. Calcification level is one of the best predictors of cardiac disease so controlling it is vital. The K2 enables an MGP protein to work well. Taking 5000 IU of vitamin D3 boosts production of MGP and 10,000 IU of Retinol vitamin A helps control calcium by improving MGP production and lowering kidney stone formation.
      Don’t skip the other paths to cardiac health such as adopting a low carbohydrate diet, improving nitric oxide function with daily arginine between meals, reducing triglycerides with 100 mg of plain Niacin several times a day, and taking the gamma form of vitamin E to reduce clotting.

    2. Yes Susan, Vitamin K2 is helpful in improving arterial calcification. MK4 is the form most useful for that, while MK7 is the form most useful for improving bone density.
      VK2® provides both MK4 and MK7

    1. Take the vitamin D3 for its own benefit, usually blood levels of 50 to 80 ng/ml in American units are optimal for best health. This tends to be a dose of 10,000 IU of D3 for those with normal fat absorption. The vitamin K2 works with the MGP proteins that are boosted by taking more vitamin D3.
      Have a look at taking the MK4 form of vitamin K2 which is ,what the body makes for its own use. The MK4 functions in many more places than the MK7 form does.

    2. Jeronimo,
      The idea is to have sufficient Vitamin K2 to activate all of the Vitamin K2 Dependent proteins (VKDP) in your body.

      That exact amount has not been exactly determined.

      Certainly, taking Vitamin D3, which stimulates the production of VKDPs, increases the demand for Vitamin K2.

      Numerous factors which might impact how much Vitamin K2 is needed include: how much Vitamin D is being taken, what medications are being taken, overall health status etc.

      Each capsule of VK2® contains 5mg of MK4 and 100 mcg of MK7. Its recommended to take one capsule of VK2® for every 5000iu of vitamin D3

  62. I have a hereditary stroke possibility, from the female line. Have you heard of this and do you think Vit K is involved?

    1. While improving general circulation health will help prevent strokes, the next thing is to figure out if these are strokes due to clotting or due to bleeding, then address the specific cause. Strokes can be caused either due to clotting or due to bleeding.
      The MK4 vitamin K2 would help with general circulation health and if there is artery calcification present, it improves this and the condition of the blood vessels. This should help both kinds of strokes. There can still be problems with artery narrowing or excessive clotting that need to be addressed by lowering insulin levels with a low carbohydrate diet, taking plain Niacin (see and looking up a variety of actors like alpha lipoid acid. Dr Louis Ignarro has an interesting book out on heart disease. The gamma form of vitamin E is effective for lowing INR and blood clotting.
      For bleeding strokes the important thing is blood vessel wall integrity. This emphasizes building the connective tissue in the blood vessels with enough protein, vitamin C, and copper.
      Don’t let the doctor tell you to not take vitamin K2, it doesn’t function strongly in clotting, has been shown in extensive readership trials to not induce clotting and has been safe even at high doses. Do have a talk with a qualified health professional on your particular stroke type. Just remember that doctors are not trained in nutrition and the medical references are decades out of date on vitamins.

      1. Youtube is a phenomenal resource because of poorly educated health professionals… if prescription drugs are not involved then they are out of the loop! I believe strokes are about blockages and if your lucky bleeding will be followed by clotting. We have moved forward much faster by sharing! L

  63. Still seeking a one dose, 300 to 360 microgram mk7 pill for mom, as she takes so many heart pills. The kicker- we prefer no soy but rather chickpea based. Can anyone help us? Thanks so much

    1. Daniel,
      If your mom has heart issues, perhaps mk4 may be a better choice . VK2 has both MK4 and MK7.
      If you visit the site, you can watch videos that explain in details

    2. Daniel —

      I came across this K2 MK-7 on Amazon: Rejuvenation Therapeutics Vitamin K2 MK-7 has 300 mcg capsules almost double the strength of any other brand on Amazon. All natural and derived from natto beans. Here’s a link:

      1. Yes I have a bottle of this in my possession but it is natto based. Mom has a soy sensitivity will this affect her? Also, the manufacture date was 2017? What do you think about that?

    3. Hi Daniel,
      Have you tried Andrew Lessman vitamins? I order all of my vitamins from him. The products contain no soy, and are all 100 percent guaranteed. He has several VK2-MK7 products. All ingredients are the best available. My mom and I have been taking his vitamins for the past 20 years and we will only use his products. He will be appearing on HSN network next month in Oct. if you want to check him out. Good luck and best wishes!

  64. Hi Chris

    I am an 85 year old female.
    I have been on the diet for at least 10 years.
    I just discovered the vit. K2.
    I have severe dizziness and am hoping that the vit K2 will help.
    I take vitamins from constantin they are very good..
    I am so happy that I am on your list

    Yours very sincerely

  65. Sorry, I should have asked about the D3 dosage also. There are tons of 5000 IU products. That would be the easiest thing to buy. I’ve read widely varying opinions about safe dosage levels. Two commenters elsewhere said that dose caused them to fall down a lot, one person breaking an elbow. When they dialed back the amount they stopped falling down. There are other concerns as well. How do we know what to believe here? Thanks again.

  66. I’m thinking of taking a D3/MK7 supplement that would give me 360 mcg of MK7 per day. This is more than all daily dosages I’ve seen, but based on the reading I’ve done, it’s probably OK. Is this correct? Thank you.

    1. Van,
      Research has not determined the maximum safe amount to take, but there are certainly many factors that need to be considered. The more vitamin D you take, the greater the demand for vitamin K2. For a very informative video on topic, please visit http://www.

  67. Hello!

    Have you heard of the supplement Mega-Quinone K2-7 from Microbiome Labs? I didn’t see it in your reviews and I am wondering what your thoughts are on it?
    I’m asking in regards to someone who has Osteopenia. In the “Calcium Paradox” book you mentioned in your recommended reading, the author recommends 240mg MK-7 for those who have Osteopenia or Osteoporosis, and it also mentions K2 supplements with K1 included in them are not necessary. The Mega-Quinone K2-7 supplement actually has 320mg of MK-7 from fermented chickpeas and includes 100mg K1 and Magnesium “for absorbability” purposes. Do you believe this dose is too high? What if that person is taking a high dose of Vitamin D3 in conjunction? Would they then be ok as long as they up their Vit. A intake?

  68. What about MK7 re estrogen production related to potential breast cancer reoccurrence in women treated for breast cancer?

  69. I ordered a bottle of Ultra K2 from Stop Aging Now. The K is listed as menatetrenone. One capsule has 15,000 mcg and they recommend 1 capsule per day. Is this amount too much? The bottle says that is 12,500% of the daily dose!

    1. That is a reasonable dose for the MK4 form of vitamin K2. Doses used in research have ranged from 1.5 mg to 135 mg daily with 15 mg three times a day (45 mg) being the most typical research dose. This gives the best results in research trials but lower doses have been tested successfully.
      I had great success in taking 1.3 mg for 12 months with artery calcification. I notice a few improvements in going to a 6.5 mg daily dose so many people can be helped with a 1 mg to 10 mg dose. If you have hazardous medical concerns with bone loss or artery calcification, taking the 45 mg per day dose can be justified as this requires the best possible results.
      Medical references have been very conservative on qualifying MK4 vitamin K2 with a traditional 120 mcg dose for Vitamin K. This dose ignores all the many research papers on MK4 and that the Japan Ministry of Health has listed MK4 vitamin K2 as a treatment for cardiac disease and bone loss since 1995. Th eMK4 form has been tested as low in side effects even at doses of 135 mg (135,000 mcg) per day, so the 22.5 mg is safe.

        1. Tamer,

          I suggest you visit
          There is a ton of info that you can read and there is also 2 videos that you can watch.

          The short answer is that both mk4 and mk7are important as they each have different qualities. Yes vitamin K2 can (and should) be taken at the same time as Vitamin D3

      1. Just came back from the hospital where moms Echo showed mitral valve area going up from 0.96 cm squared to 1.12 cm squared in 6 months. Using daily five mg MK4 Carlson brand and 180 MCG mk7 utzy Naturals brand. I think we’re going to double the dose of both. Please comment!

  70. I have heart disease , 3 vessel stenosis, I believe statins help to stabilise the plaque by calcification, I want to take K2 MK7, will this destabilise the atherosclerotic plaques and make them more prone to rupture, when K2 MK7 starts to remove the calcium build up , I am struggling to find a suitable answer to this question.

    1. In 2007 I had three vessels calcified to 90% plugged. Went on statins , cholesterol down to 131 in 2015. In 2016 learn of K2’s. started on MK7 and MK4 back and forth. Cholesterol shot up to 281 last year. went back on statins for a month plus B3 till my net test, Cholesterol down to 181. two months ago started on thoren vitamin D3 1000IU/mk4 . 2 drops 200mcg , vitamin d3 5000IU, Boron 3mg, Vitamin A 2662 IU, Mega COCQ 10, Astaxanthin 12mg. Had particle test two weeks ago–cholesterol 198, partial size and number in range. I’m still standing upright.

    2. This is not an in-depth answer but it does come from the website of Dr. Kate Who wrote the book… Vitamin K2 and the calcium paradox…

      Since K2 reduces plaque, won’t it increase the risk of a clot or heart attack as pieces of the plaque break off?
      This is a FAQ since as we understand K2 helps reduce arterial plaque it is easy to imagine it being chipped away or breaking off in chunks. That is not the way K2 shrinks plaque and K2 supplementation has never been associated with a cardiovascular event. In fact, vitamin K2-dependent proteins make plaque more stable and less prone to rupture. Recent clinical trials for reducing plaque in a group known to be at high risk for calcifications used MK-7 in does of around 360 mcg per day with no significant adverse effects (a few participants experienced stomach upset at this dose).

    3. I don’t know if this would help but it might be worth reading:

      I have been taking this Arterial product 2X per day which is twice their article recommendation and I take additional 100 mg. Pycnogenol at 2X per day since some studies seemed to have some stabilization effects at high doses. This is a fairly expensive treatment at these doses.
      I also take K2, D3 and A.
      Won’t really know if this is working for me until my next scan in Nov 2019. but it looked like something to try since I have 2 blockages at around 90% as of last Nov scan.
      This is not a recommendation for you, but I felt that in my case it seemed worth a try.

    4. Gary, I have some stenosis in 2 vessels and a calcium score of 579 3 years ago, probably a little higher now.

      The thing is to stop focus on removing or stabilizing plaque, but on stopping depositing it. To do that I went on a whole food plant-based diet with no added oils, per Dr. Esselsstyn. Great results, not as hard as I had thought. But it does take grit and determination at first. It has a good track record, and you can find out more by watching the movie “Forks Over Knives”.

      It works for me, my doctor agrees, and I’m on zero statins, BP went from 140/90 to 110/70, not bad for 73 years old. No meds at all, no stents, nothing. I climb long flights of stairs several times a week and workout with weights.

      I believe that so long as you are providing dietary building blocks for plaque, the body will use them and to hell with all your vitamins and drugs, the disease will progress anyway. By not putting in things which damage your endothelium (inner layer of cells inside the artery walls) it works to stop and reverse the disease. I would advise this diet for a few months, then start program of exercise to reverse the disease WHILE on the diet. Don’t exercise prior to the diet, it can raise risk a lot. besta luck, pal Bob

    5. ..BTW, coronary calcium scores may vary and there’s no really good studies on them responding to diets and other things, however, it is known that when plaque begins to go away on whole food plant-based diets, calcium scores at first rise. This is the body throwing in some extra calcium to stabilize the softening plaque and prevent ruptures and lessen clot risk. It knows, it’s been there before in the millions of years of our evolution. This data is per Dr. William Castelli, former director of Framingham Heart Study. Calcium is about 20-25 percent of plaque volume, so if you lose 10 percent soft plaque and gain 10 percent calcium, you’re way ahead. Exercise will drive collateral artery formation around the blockages, but is risky if the diet is atherogenic (sat fat, cholesterol) since it weakens the fibrous cap over the plaque. The whole food plant-based diet strengthens this cap and makes you heart attack proof from plaque ruptures, which is 90 percent of heart attacks right there. Dr. Esselstyn says it takes about 3 weeks for this to happen on the diet. I’d say give it 2-3 months before exercising in earnest. I have seen 2 people taken out from my gym on gurneys in the same week, they probably thought if they exercised, they could eat whatever they wanted. This is backwards!! If you eat right you can exercise all you want is more like it.

      1. Well, from my understanding, artery calcification is mostly caused by chronic inflammation not high cholesterol per se. A low carb/sugar diet along with avoiding Veg/Seed oils (PUFAS) at all costs. A whole foods, Ketogenic diet along w/ a targeted D3, K2 (MK4 & MK7), Magnesium, Zinc, Vit A. , etc. I’d check out Ivor Cummins interviews/lectures/vids on YT for starters. I try to keep updated & take in as much info as I can. It’s been said recently (not in any mainstream media way mind you) that Diabetes IS Pre-Heart Disease. A Ketogenic diet (or some cases simply a low-carb diet) reverses T2 Diabetes & Pre-T2 Diabetes. So, it stands to reason.

        1. PUFAs aren’t bad for you. Let’s not demonize another nutrient. The problem with some PUFAs, specifically the omega-6s, is not keeping them in balance with the omega-3s. See for one example of an important and necessary omega-6 PUFA.

          Still, don’t use seed oils to get them—maybe try some lard—because throwing off your fatty acid ratio is hardly the only problem with industrial oils. They go rancid, oxidize, and are apt to contain residues of solvents and other noxious chemicals used in their processing.

          1. Not for nothing, but when I said PUFAs, I did in fact mean Seed Oils/Veg Oils, kinda goes without saying. Every lecture or interview I’ve ever watched or read on this subject, everyone typically using the term PUFAs for Seed Oils. I thought it safe to assume you knew what I was talking about when I used the term PUFAs. However, your critique is duly noted.

          2. Are you talking about Flaxseed Oil? I just ordered a bottle to help with my dry eyes. Please let me know, TY

          3. If i may chime in…PUFA has been used a lot in health circles to refer to industrialized oils (corn, peanut, soybean, canola) and we as an audience tend to get a bit robotic with the term. Not all PUFAs are bad, but my understanding is that they all turn bad once heated. I mean, look at cod liver oil (high quality ones like Rosita or Dropi), they have omega-3 DHA and EPA which are PUFAs (to my knowledge). Even oils like walnut have their place in our diet according to Sarah Pope, a member of the Weston Price Foundation.

  71. Is there any way to counteract the insomnia caused by mk-7? I need to take it but I need my sleep!

    1. Do you take magnesium? Perhaps take K2 in the morning and Magnesium citrate in the afternoon? I’ve found K2 and Mg work in unison for me (but I don’t have to take them at the exact same time)…

    2. Hi Michelle,
      You have the classic symptoms of being sensitive to the MK7 form of vitamin K2. There are anxiety, sleeplessness, a thumping heart beat, and possibly raised blood pressure. The solution is to stop taking the MK7 vitamin K2 and switch to the MK4 form which is native to all mammals and has few side effects in the human body. Typical doses for the MK4 form are 1 mg to 5 mg, and higher if there is a serious medical risk. Carlson makes a good 5 mg MK4 only tablet and Thorne makes a liquid MK4.
      The MK7 has a half life of 3.5 days in the body so I may take a while to clear out. Know that natto is a fermented bean that contains very large amounts of MK7. The MK7 is made by bacteria and it is only partly functional in the dozen tissues that MK4 works in.
      If the MK4 is being taken to improve bone strength or reduce artery calcification, note that 5000 to 10,000 IU of vitamin D3 and a similar amount of Retinol vitamin A will help by boosting production of the calcium handling proteins that MK4 activates. Taking 200-400 mg magnesium and 12 mg boron will also be helpful.
      In my case I resolved a 20 year case of artery calcification in 12-18 months by taking 1.3 mg of MK4 daily. So the MK4 form will be more effective and and work better than the MK7 form.

      1. David,
        Do you have a blog where you talk about the details of your journey of resolving the calcification? I am very interested….thank you.

      2. Hi Mr. Sander:
        When you resolved your 20 year problem did you get a calcium CT score before and after.
        If so, can you please share with us what the scores were?
        I used similar amounts Boron at the 12 mg and magnesium citrate at 800 mg per day (the Carlson Mk4 2x day) same D and A plus 360 micro’s of MK 7 and a strict Mediterranean diet and my CT score increased at 35% per year.

        1. Hello, please help me. I took Mk7 by Jarrow for about a year and added coral calcium to the mix and my head started to grow. Im not sure why I continued to use it but I ended even getting vitamin d3 and k2 drops after and it grew more. Now I can barely stand my appearance because I feel it made me look worse. Is there any possibility it can reverse?

          1. Have you asked any guys? I’d find that kind of hot, myself, brainy lady with cute face wow. I think if you stopped doing the calcium it should stop happening, though, just my opinion, I would do that. I’m bald, so my head bigger, probably not good. Best of luck,

          2. Heather, more likely your eyes got smaller or your brain got smaller so your head looks bigger. The only documented head growth is among bald headed men. That’s why bald headed men like Robert Luhrs are smarter.

          3. Heather,

            All kidding aside you may ask your physician to test you for acromegaly, excess growth hormone. There are good reasons to believe that K2 and calcium supplements would contribute to acromegaly skull growth. The cure is pituitary brain surgery.

        2. Well, actually my head got smaller since taking vitamin K2., then again I lost 40lbs. So if the weight is the same then the head size should be the same. My dad at work played a trick on a guy who just got a raise and told everyone else. He put a one inchstrip of newspaper inside his hatband every day, then had everyone come around and watch while he put on his hat. Really freaked him out.

      3. similar amount of Retinol vitamin A will help by boosting production of the calcium handling proteins that MK4 activates. Taking 200-400 mg magnesium and 12 mg boron will also be helpful.
        In my case I resolved a 20 year case of artery calcification in 12-18 months by taking 1.3 mg of MK4 daily. So the MK4 form will be more effective and and work better than the MK7 form

        such huge dose of retinol “am concerned for side effects ‘are we deficient nowadays in vitamin a at all ?
        your great results with mk4 doesn’t tell me anything about mk7 would miss to give you same results “

    3. The solution to this is to stop taking the MK7 and replace it with an equivalent 1 mg to 5 mg dose of an MK4 only form of vitamin K2. Virtually all of the time this solves the problem.

  72. Hi Chris. Thx for great info on K-2. Perhaps you might be able to add clarity on blood thinners and K-2. You mentioned anti-coagulant coumadin. What about Plavix/clopidogrel, which differs somewhat is I believe anti-platelet. I’ve read that K-2 and Plavix will not interact. Perhaps you can address?!…

    I know, I should contact my doc, but my cardiologist is useless (MI last year at 56, 2 stents, am now solidly LCHF and endeavoring to prolong life, excited about K-2’s reported mortality reduction….

    1. Hi, I have same question. I take Plavix, aspirin and i’m not sure if it is okay to take K2. My cardio did not say anything about it when i asked. Bro, did u get answer for this ? Thanks.

  73. I’m trying to find a supplement for mom who has very high valve calcification, specifically in the mitral valve. I’ve had her on MK-7 150mcg daily (“Solaray triple strength K2”) for two months and not sure if this is helping. Thinking we need the MK-4 as well. Is this better for valve calcification? The ones recommended may require two dosages to get where she needs and she is already taking so many pills for her heart. Thanks so much for your input. Daniel

    1. I’m no doctor but I’ve experienced better outcomes from switching to mk4, as in the calcification on the rear of lower front teeth chips away by itself/more easily, and my skin improves. I can’t speak of valve/soft tissue calcification but it makes sense evolutionarily to me that mk4 would be more necessary and effective than mk7. I think Thorne Research drops are a good brand and they come along with D3. Add some vitamin A (or consume liver regularly). I would also suggest taking Magnesium citrate 100-200mg as well – I’ve noticed that K2 and Magnesium work better together for me. These are the only supplements I take. The book, The Calcium Paradox, explains well how these vitamins interplay with each other.

      1. Thanks, I found Jarrow K-Right which has 1500 mcg of MK-4 and 180 mcg of MK-7, plus 2000 IU D3 along with K1 (not sure if important or problematic). Anyone seen this one?

        I’ve also heard vitamin A. Can she take beta-carotene or does it need to be A and how much? Thanks again for your advice.

        1. Hi there,

          Beta-carotene is the plant version of vitamin A and nowhere near as bio-available to humans as the animal-sourced version of vitamin A (Retinyl palmitate or acetate). Liver or pâté is best, but if not consuming those things, a good supplement may help. I take 5000iu retinyl palmitate per day or sometimes just 25,000iu per week instead…

          1. In all my reading I’ve never heard about the vitamin A importance can you please elaborate on that. Thank you Katy!

          2. This is quoted directly from Kate Rheaume-Bleue’s book: ‘Vitamin A plays a valuable role in managing the body’s need for vitamin K2. On a molecular level, it is precisely this misunderstood role that gave vitamin A an undeserved bad rap. Vitamin D stimulates the production of vitamin K2–dependent gla proteins, thereby increasing the body’s demand for vitamin K2 and the potential to benefit from K2. That makes vitamin D a superstar because the more vitamin K2–dependent proteins you make, the more calcium you can direct into bones and away from arteries, if you have the K2 to activate those proteins. So vitamin D looks good. Here’s where things get tricky. Working together, A and D synergistically improve osteocalcin production.’

            This is only a fraction of the info she goes into in her book. I can’t recommend it enough.

          3. And this:
            ‘Vitamin A has a K2-sparing action; having adequate amounts of retinol reduces the demand for K2, allowing your body to get by on less menaquinone.’

          1. Adding the Retinol vitamin A results in the formation of more Matrix GLA proteins which are activated by MK4 vitamin K2. This was used in one trial to reduce the number of kidney stones some patients were getting from high dose vitamin D3 treatment. So vitamins K2 and A work synergistically to control calcium metabolism to good ends.
            Note that vitamins A and D3 are needed in a balanced proportion or ratio and there is little specific research on this. I found that an optimal amount of each was 10,000 IU of D3 and 30,000 IU of Retinol vitamin A.

        2. There is no harm in taking Vitamin K1, but it is not needed. Vitamin K1 deficiency is very rare. Vitamin A is a good to take, but taking beta-carotene is not such a good idea.

          I recommend vK2 which contains both MK-4 and MK-7. Each capsule is intended to be taken with each capsule of 5000 iu Vitamin D3

      2. Does anyone know the best ratio of D3 to K2? For years my mom was taking 5000 iu D3 without K2 at all. I now have her on 1500 mcg MK4, 180 mcg MK7, and this is combined with 2000 iu D3 daily. Since I am concerned about not overloading her again with D3, is this balance, combined with magnesium, safe? Is 2000 id D3 daily going to put her back in dangerous territory? Thank you, Daniel

        1. Its not an easy answer. In general the idea is to have enough vitamin K2 to activate all the Vitamin K Dependent Proteins (VKDP).
          Vitamin D stimulates the production of VKDP, which is why vitamin D increases the demand for Vitamin K. That being said, there is no harm to take more vitamin D3 (up to a limit) but it wont provide additional benefits w/o having sufficient vitamin K to activated all the VKDP that the additional vitamin D3 would stimulate. Thats for vitamin D3. Vitamin D2 on the hand can be toxic if taken too much.

          Another point to consider is that MK4 is more suitable for activating MGP, while MK7 is more suitable for activating OC.
          That’s why its important to supplement with both MK4 and MK7.

          The bottom line is that the exact ratio of vitamin K2: Vitamin D to achieve activation of all VKDP has not been determined yet and would depend on if we are talking about MK4 or MK7.

          vK2 contains 5mg of MK4 and 100 mcg of MK7. We estimate this to be an optimal amount to take with 5,000 iu of vitamin D3

          1. Eric summarizes in this post what I learned by studying the literature and Dr. Masterjohn’s summary.

            One addition is that Vitamin K2 substitutes more efficiently than ubiquinol in the mitochondrial electron transport chain. Cross comparison of bicycle teams showed 7% improved aerobic performance with 200 mcg of K2 in the diet. 7% is enough to win a bicycle race. Lance Armstrong commented on his web site that a high dose of K2 causes finger tips to tingle. Mine do because I supplement with my own fermented Bacillus subtilis/liver/limburger pate. I guarantee you Lance Armstrong was taking more than 200 mcg K2 per day. I find it amusing that he was sanctioned for blood doping and testosterone when perfectly legal K2 gave him >25% aerobic advantage. ☺☺

          2. I’m still struggling with a decision that will affect mom’s hypercalcemia outcome: She dosed 5000iu without k2 for years. Has valve stenosis. Now on mk4 and mk7 but do I even need D3? I don’t want any additional calcium in the bloodstream but rather to stabilize or remove it. Please let me know if this is correct thinking. Thank you.

          3. The most sensitive and numerical test for progress reversing calcification and stenosis is pulse wave velocity. Accurate home testing devices were offered by Nokia for $1000 until FDA demanded an approval. Nokia no longer offers the device in USA. Smuggle one in from Europe. FDA approved devices cost $10,000. Find a clinic.

        2. Best way to know, and perhaps the only way to really know is a D3 blood test. They are not very expensive and seem to be accurate.
          For my clients, I look for a value of 60 ng/ml or above – I prefer 80 ng/ml as an excellent value. I have some clients in the 90’s.
          I go with 5000 mcg MK4 2xDay and 400 mcg MK7 along with 5000 up to 10000 vitamin A pre-formed.
          I can’t give you medical advice for your mother (or you) but these are the values I use for myself and clients. Your mother may have different goals/values.

          1. Thank you for this great information. I am trying to stabilize or hopefully improve her stenosis and calcification without doing something that would worsen it. Mom is a bit heavy and her D3 is low, 40. I had her on 5000 iu for years without K2. Now only 2000 iu as I am afraid to bump it up again.
            it seems like my values are on the low side, but she is taking so many heart pills. I hope what I am doing will be helpful, comments appreciated.

          2. Additionally….how important is vitamin “A” for this, as I read hardly anything about it. More pills for mom…trying to avoid it.

          3. My MK7 supplement we prefer is sourced from soy. I know there are other options but we are using this one right now because we like the other ingredients. How critical is this if you have a possible sensitivity to soy? It seems like such a small amount. Thank you. Daniel

          4. For artery calcification several things are involved. The MK4 vitamin K2 is essential to carboxylate the Matrix GLA protein that reverses calcification. Taking the vitamin D3 is fine as this boosts the levels of calcium handling proteins. In addition, taking the Retinol form of vitamin A also results in better Matrix GLA production and this is reflected in how Retinol is able to reduce rates of kidney stones. She should also get magnesium daily.
            My best guess for this series would be.
            5000 IU of vitamin D3
            15,000 IU of Retinol vitamin A
            5 mg of MK4 vitamin K2 three times a day. More would be acceptable.
            200-400 mg of magnesium citrate or a more gentle taurate.

          5. Thank you so much all. I’m wishing I had some test feedback to determine if the vitamin regimen is working. Those scans and such are not readily available here in Pittsburgh PA. I’m wondering if I can assess mom by checking her on a monthly basis with regard to activity tolerance. I have no other way to know. Should I expect to see a change within months, or years? She was supposed to have mitral valve surgery a few months ago, and we decided too risky. Thus the vitamin and lifestyle changes.

        3. See if you can get her eating a few carrots each week for the A. 2 average carrots/day is a nice amount to load up on, then maybe one a day would be good. My own remedy for my calcium is a whole food plant-based diet. Not for everyone, but the ones who do it, never have any more heart problems, strokes, even diabetes is eased off. The study participants who didn’t do it, most of then either had heart attack, stroke, or death in a few years’ time. But they were only 10 percent of the group, the rest had zero of those things. So it is do-able. Dr. Caldwell Esselstyn did the studies on this.

          1. Animal-derived vitamin A is far more bioavailable than beta-carotene from carrots. A significant percentage of people can not even convert it at all! I’m a big fan of animal-based diets for being far more nutrient dense. But you must do your own research and decide for yourself.

        4. Hi Daniel…there is a product from Forefront Health that combines these three fat soluble vitamins in one convenient bottle. It’s liquid, so no more pills to take. The ratios are good too, each serving size is 7 drops and you can take a dose with each meal if you prefer more than one serving per day. I’m not affiliated with this company, I simply think it’s a very convenient and SUPER CLEAN product that is very easy to take.

          Ingredients: retinyl palmitate (Vitamin A), cholecalciferol (Vitamin D3), and MK-4 menaquinone (Vitamin K2), MCT (coconut oil)
          Other Ingredients: None

          One serving provides 5,000 i.u. vitamin A, 1500 i.u. vitamin D and 2 mg. vitamin K2 as Mk4.

          I try to purchase when it goes on sale for extra savings.

          1. Thank you very much, I see much information about MK-7 but not much about vitamin A in my studies. We will try to get the vitamin “A” in as well. I am wanting to have MK-7 in the mix as well based about my research. I will look into it but right now we are using Jarrow K-right. Daniel

          2. Kind of annoying that I can’t reply to nested comments, so this is the most relevant one.
            Look to nature to find correct ratios of vitamins. For example, cod liver oil (Rosita or Dropi) list their oils as having 10 times more vitamin A than vitamin D. I also heard from Dr. Shiva that we should be getting ten times more vitamin A than vitamin D. I don’t know why that is the case, but reading some of the comments here suggests that vitamin A spares vitamin K2 so that we would needs less k2 to trigger the synergy between A and D.

            Dr. Weston Price referred to vitamin K2 as the x-factor, and most of his research involved native population and their diets, rich in K2, and how they’ve never seen a dentist in their lives and never developed dental issues until some of them were introduced to grains or industrialized foods.

            To quote my favorite clothing brand Icebreaker:

        5. There is no specific proportion of vitamins D3 and K2. Below a healthy age 40 we generally make enough K2 from vitamin K1 to have an adequate supply. Above the age of 40, production of MK4 vitamin K2 drops off gradually resulting in lowered calcium metabolism where bonevloss occurs and artery calcification starts. Giving vitamin K2 to young people is not likely to show an effect.
          So the basis for dosing vitamin K2 would be in proportion to the symptoms of low vitamin K2. 1 or 2 mg will do a lot over time for healthy people. A 5 to 15 mg dose would be good for those with more serious health problems. If the patient is in immediate danger from bone loss or artery calcification, the most effective dose used in research was 15 mg with each meal containing some fat for a total of 45 mg a day.

          1. Hi David,
            “So the basis for dosing vitamin K2 would be in proportion to the symptoms of low vitamin K2. ”

            AFAIK the symptoms of Vit K2 deficiency are osteoporosis, soft tissue calcification and kidney stones. All requiring scans to determine. How do you know how much K2 is required to reverse these? Were you getting repeated scans and adjusting based on the results?

            Similarly, in another comment you said that you found the optimum amount for you was 10,000IU D3 and
            30,000IU of A (seems a lot of A). How did you determine that? Does the form of A make a difference? I can only buy retynil palmitate here.

            Lastly, do you have a reference for the study that used 45mg/day K2 for arterial calcification? I know they use 45mg in Japan for osteoporosis but wasn’t aware anyone had treated calcified arteries with it in a formal study.

          2. Re: young people. I would guess from historical and almost lifelong symptoms of acne resolved in recent years by supplementing K2mk4 and Magnesium that I am genetically a poor converter of K1 to K2. I’ve been giving K2mk4 and Mg to my kids and have noticed whiter teeth and resolution of blocked pores on my tween. They may have inherited my poor ability to convert K1 to K2.

            Basically, the only supplements I take are a replacement for eating liver, which I can’t abide (pity).

          3. BTW regarding osteoporosis and bone health generally I strongly recommend the late Robert Heaney’s articles at
            If you are not familiar with Dr Heaney he was the initiator of the long-running Omaha Nuns Study into osteoporosis and a leading authority on bone health, calcium metabolism and Vitamin C. This obituary outlines his achievements

            If I can summarise Heaney’s articles on correcting osteoporosis you need:
            – adequate calcium in your diet
            – adequate Vitamin D to absorb that calcium
            – adequate protein to rebuild bone (bone is 50% protein and only 20% calcium)
            – phosphorus since the calcium in bone is calcium phosphate. Hence the best source of Ca is dairy which already contains the calcium phosphate.
            – Vit K2 to direct the calcium to your bones.

            He points out that calcium is so essential to your body that it is tightly regulated and if your calcium intake today is inadequate then your body will tear down some of your bone today to get that calcium, but in the process also destroys the protein matrix. In order to rebuild that bone in osteoporosis patients you need more than 150% of the RDA of 0.8grams of protein per Kg of body weight. (So much for the RDA!)

            The way that the body increases that bone teardown is through the release of parathyroid hormone (PTH). To quote Heaney:
            “The concentration of PTH circulating in our blood stream is, thus, a reflection of how close our serum calcium level is to the set point, or how hard the body has to work to keep it there. When calcium intakes are low (either because the food contains little calcium or because, with vitamin D deficiency, we’re not absorbing efficiently), PTH levels will typically be elevated. And, accordingly, when absorbed calcium intakes rise, PTH levels fall, until they reach some minimum value below which they drop no further, no matter how much additional calcium we may consume. Other things being equal, a low PTH level is an indication of calcium adequacy.” Conversely high PTH implies either low VitD, low dietary calcium or both together. Heaney then goes on to show that PTH flattens out at a serum Vit D level of 125nmol/L or 50ng/ml, although with a degree of individual variation.

            I mention this because when my mother’s blood test showed high PTH her GP suggested referring her to a surgeon to get her parathyroid gland removed! No mention of calcium or Vit D status. It appears that modern medicine’s motto is “when in doubt, cut it out!” Sheesh.

          4. EXCELLENT post Stuart!!! I agree 100% and think everyone should have their PTH tested.
            Thanks so much!

    2. Tell your mom to back up forty years and eat properly. Every day should include liver, fresh greens, strong flavored fermented foods such as kefir, buttermilk, labneh, brie, feta, Swiss, Limburger, saurkraut, natto, miso, tempeh, kunjukjian, ambrosia, pickled fish, liverwurst, salami, molasses, pate, reheated leftover vegetables, hummus, kimche, pickled beets, pickled cucumbers, salsa,….

      1. KGB, those foods would KILL anyone with histamine intolerance. Please educate yourself before posting such ignorance.

        1. @Kelly

          I know this is a really old thread but maybe someone will see my reply. You CAN eat fermented foods with histamine intolerance. Supplement with DAO with such a meal. It neutralizes histamine in foods. I also recommend supplementing with digestive enzymes to make sure.

    3. I highly recommend vK2, which contains pharmaceutical grade MK-4 (5mg , 100% trans form) AND MK-7 (100 mcg, 70% trans form)

  74. Wondering what is the optimum amount of Vitamin D3 to take with 200 mcg of Vitamin K2MK7? I am on a ketogenic/keto-carnivore WOE. I live in Saskatoon, SK, Canada and am a red-headed, 62 year old woman. I have heard that red-heads make their own Vitamin D but not sure what kind. Am taking 200 K2MK7 with 1000 mcg Vitamin D3, presently.

  75. Hi Chris,

    Love your work. My own experience with K2 has been an interesting one. I’ve been using it for 3 years after stumbling into both your information online and Dr Kate Rheueme-Bleaue’s book. It coincided with when I first started eating low carb, healthy fat. At first I noticed improvement in my nails when consuming significantly more grass fed butter and that’s when the whole K2 a-ha moment occurred.

    I’ve experimented with both K2 MK4 and MK7 and found the effects of using mk4 far superior, measurably so. I think it lines up well from a evolutionary standpoint and is probably why mk4 is used up so quickly by the body.

    I would also bet money on me being a super-lousy genetic converter of K1 to K2.

    Benefits of mk4 vs mk7:
    No dental calcification – the stuff literally chips away once I change to mk4.
    Significantly improved skin – back and facial acne disappears.

    As long as I take K2 *with* daily Magnesium, my 40+ yr nail biting habit literally stops. I’ve tested this a number of times, if I stop taking either K2 (either mk7 or mk4 do the job) or Mg, the urge to nibble my nails creeps in over about a 10-14 days. Once I resume taking both supplements, the urge to chew goes after about 2-4 days.

    The only supplements I take daily are:
    K2(mk4)/D3 Thorne drops (5-10 drops twice a day)
    Magnesium citrate (100mg)
    Vitamin A (5000iu)

    I probably won’t bother with K2 mk7 supplements anymore as I eat plenty of the relevant cheeses and/or sauerkraut, and I’m convinced they’re less important than mk4 anyway….

    If only I enjoyed eating liver, I could drop the supplements altogether 😆

    1. Oh, I forgot to add…

      I’ve been giving my kids the same K2 as me for the past 3yrs so : 6-9mths of mk4, then a switch to mk7 for about 18mths and now a recent switch back to mk4.

      They’re teeth are measurably whiter when taking mk4 compared to the mk7 (which made zero difference). Takes about a month to see difference.

      My 8yo son recently had to see a maxillo-facial surgeon regarding an underbite, and we’re going to leave it a year and have another look in 12mths time. I’m very interested (and hopeful) that switching back recently to K2mk4 will contribute to an improvement (although we’ll never know for sure if it was the K2 that made the difference or just normal growth correction – fingers crossed, I’ve heard of adults online claiming improvements of jaw structure using K2… we’ll see…).

      1. Regarding underbite and jaw structure, look up an Orofacial Myofunctional Therapist in your area. Exercises are very effective at correcting jaw structure in young children!

    2. So interesting about your nail biting, because I’ve also noticed magnesium affects that for me but lately it hasn’t been helping. Do you take all 3 supplements at the same time? Have you ever taken them on the same day but at different times to see how that affects? Also, what time of day do you take them? I’ve noticed timing can have a big impact for my sensitive body. Thank you so much in advance!

  76. The fact that other than a few specific naturally occurring foods have high levels of K2 leads me to believe that an assumption that 100mcg a day is needed or 200mcg is not based in reality. The reality is that it seems you would be lucky to be able to get more than 50mcg a day without actively trying to consume multiple foods on this list, which I am sure people historically did not have access to all of these foods at any given moment like we do today. If you get to page 12 you see that the levels in foods vary widely. Given that Weston Price had such great results when adding in small amounts of butter oil and the levels vary widely from one butter to the next leads me to believe only small amounts of vitamin K2 are needed.

    1. Sir,

      Humans evolved over more than a million years. During that period the bulk foods were fresh vegetables. High K2 bacillus subtilis are swimmers moving up plants toward oxygen during rain. Green leaves and fresh vegetables are high in Vitamin Kf2.

      In addition the primitive food over a million years was a community porridge recooked day by day. Bacillus subtilis are heat resistant spore former not toxic and they produce plentiful Vitamin K2 during cool porridge periods.

      Lance Armstrong reports that high intake of K2 causes the fingers to tingle. He should know. He had an aerobic bicycle lab in his home. He titrated his bicycle aerobic performance versus intake of multiple supplements by sending out blood samples for analysis. He won 5 Tour de France races.

      Independent physiological athletic research comparing bicycle teams with and without 300 micrograms per day of K2 showed 6% improvement of aerobic performance on this low dose of K2.

      I take enough K2/day to achieve tingling in my fingers. I grow my own Bacillus subtilis and blend it into a liver/Limburger cheese pate. I dare say I get more than 1 mg/day. I cannot afford outside analysis like Lance Armstrong.

      I suggest to you that OVER 1 mg/day of K2 was the norm over a million years of human evolution.

      1. K2 might have played a role in Armstrong’s career but EPO, steroids, etc were the elephants in the room. He’s worthless

    2. Industrial farming helped kill K2 in our diets (here in the USA). I’m sure our natural K2 intake was a lot higher eating grass-fed meats, grass-fed butter instead of factory farmed grain-fed meats/butter. If one had a healthy diet with a combination of grass-fed meats, grass-fed butter, eggs, and the right cheeses before our grain-fed factory farming took over the country, I believe our K2 intake probably rivaled a diet high in say.. Natto consumption like parts of Japan. At the very least, we weren’t deficient in K2 (before factory grain-fed farming).

      1. I read on nutritionfacts dot org that in former times our diet included bugs, dirt and feces, all high K2. We make it in our colons, but it’s too far down to be absorbed. Termites are loaded with K2 and gorillas crack open rotting tree trunks and logs to get at them.