Dr. Chris Masterjohn talks about Balancing Calcium and Phosphorus in the Diet, and the Importance of Measuring Parathyroid Hormone (PTH)

Mastering Nutrition 9: Balancing Calcium and Phosphorus in the Diet, and the Importance of Measuring Parathyroid Hormone (PTH)

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In this episode, I answer a listener's question about whether I am worried about my phosphorus intake and whether a high phosphorus intake is ok as long as it is balanced by calcium. I describe the biochemistry and physiology of the system that regulates calcium and phosphorus, their distribution in foods, how to determine the right balance in the diet, and how to use parathyroid hormone (PTH) as a blood measurement to assess whether the dietary balance is working for an individual.

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Before moving on to the show notes, check out my new logo above! With a very small investment I got this from 99Designs. I'm really happy with it as a low-cost replacement for what I had before and I want to thank all the people who rated and commented on the designs when I circulated the request on Facebook and Twitter.

Show Notes for Episode 9

If you want to skip around within the episode, this will help you navigate:

00:32 Introduction
02:16 The listener’s question on Ca/P
02:53 Outline of the episode
05:26 Roles of calcium and phosphorus and distribution among foods
13:56 Physiological principle of need to balance calcium and phosphorus
21:18 Role of endocrine hormones in regulating calcium and phosphorus
43:24 How different foods rich in calcium and/or phosphorus affect PTH levels (different effects of phosphorus-based additives, whole grains, meats, and cheese)
52:20 My own calcium and phosphorus intakes
55:22 Weston Price's data for calcium and phosphorus intakes in pre-industrial societies
1:02:20 Potential genetic differences in the requirement for calcium and vitamin D

Relevant Links for Episode 9

These are useful resources for better understanding the regulation of the calcium-phosphorus economy:

These are the studies I talked about towards the end:

If you know of better or contradictory studies please post them in the comments. Have any personal experiences with balancing calcium and phosphorus or using PTH to help interpret your health and dietary balance? Please share!

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  1. Hi Chris
    Do you know of any resource that I can find that has the ideal calcium and vitamin D intake for people of west African ancestry or dark skin non dairying cultures in general?

  2. Great article Chris –

    CRON-O-Meter is a better nutrition tracker than MyFitnessPal. I’ve used both. Has very reliable database (and includes phosphorus content of foods). If you go with the gold version you can also track some important nutritional ratios like cal/mag, omega6/3, etc.

    1. I’m using it now. It’s only reliable if you make sure to use certain database sources. There are tons of foods with zero values for micronutrients simply because the data isn’t present and they give you no warning. I do agree it’s better than MFP for micronutrients though.

  3. Thanks for your reply Chris. Can I ask a follow-up question please: is there such a thing as a normal seasonal variation in 25(OH)D? I am not getting any UVB over winter according to Dminder, and wondering how quickly Vit D is depleted/how low it might ebb.

  4. Hi Chris, great article and really fascinating stuff. So if I understand correctly, a diet of mostly whole foods with limited processed food would have a more normal balance if Ca and P, and parathyroid hormone would be in the lower range? I eat a clean paleo-esque diet including liver once every week/2 weeks. I don’t tolerate dairy well (lactose I think) but eat some aged cheddar and lots of butter. I tested my 25(OH)D level in September last year, which was end of winter for me here in NZ and it was 27ng/ml (68nmol/ml) which I thought was lowish, so I maximised my sun exposure over summer (interestingly I didn’t burn despite long periods bare torso, which I ascribe to having good fats in my cell membranes instead of canola oil!). I just retested my 25(OH)D and it was 28ng/ml (70nmol/ml). I was initially concerned but having read your material I’m starting to think it’s fine. I don’t think I can order parathyroid test for myself here in NZ but might look to a FM doc to do it. Interested to hear your thoughts on this, particularly my supposition that low intake of phosphorus from processed foods would lead to low parathyy hormone, which would mean my 25(OH)D doesn’t need to be very high. Thanks!

    1. Blair, I would definitely look into PTH. Yes, I think lack of processed foods is the key arbiter of phosphorus-induced rises in PTH.

  5. Thanks Chris.

    My son is two years old and won’t eat any dairy at all. I want to start giving him some bone meal as a supplement. Do you think this would be appropriate and if so, what dosage of calcium would you advise for young children?

  6. Thank you very much, very informative.
    I have to avoid milk products and thus I supplement with calcium-citrate powder (around 600 mg). Seeing that the parathyroid gland reacts so fast to calcium level changes of the blood, it got me thinking that the supplement could put much stress on the parathyroid if it is absorbed quickly. Do you think I should be worried?
    I take it split up to 3-4 doses before meals. Maybe mixing the supplement into the food or taking it after meals could mitigate the possible excess stress?

    1. Hi Peter, that’s what your parathyroid gland is there for. I think if it were a person, it would probably feel patronized by concern over whether asking it to do its job would be too stressful. Luckily, it’s not a person. So, I would just not worry about it.

  7. Hey Chris,

    Very interesting episode. The information about the phosphorus and calcium balance was new to me, but it makes a lot of sense.

    I’ve recently tried eliminating most dairy from my diet after trying an elimination diet. I felt great on the elimination diet, especially in terms of digestion, but after re-introducing dairy (albeit in large amounts) I seemed to have a very clear reaction to it with abdominal pain and cramping for almost two days following its reintroduction.

    After reading some studies that show some potential risks of calcium supplements (although they were in women), I’m wondering what are some other good sources of dietary calcium? I ‘ve heard you mention bone meal before which seems to have high amounts of phosphorus as well. Is there anything else you would recommend?


    1. Hi Seth,

      I would ignore the studies on calcium supplements. None of them are convincing of a cause-and-effect relationship but even if they were, they would still be irrelevant to someone who is compensating for dairy intolerance. Older women supplementing with calcium are often adding more than one gram to more than a gram from food yielding over two grams.

      Regarding the dairy, you should figure out what you don’t tolerate. The overwhelming probability is that it is lactose, in which case 60-day aged cheese and 24-hour fermented yogurt should be tolerable. But if it is casein (or something else), the practical implications are totally different.

  8. Hey Chris,

    Very interesting episode. The information about the phosphorus and calcium balance was new to me, but it makes a lot of sense.

    I’ve recently tried eliminating most dairy from my diet after trying an elimination diet. I felt great on the elimination diet, especially in terms of digestion, but after re-introducing dairy (albeit in large amounts) I seemed to have a very clear reaction to it with abdominal pain and cramping for almost two days following its reintroduction.

    After reading some studies that show some potential risks of calcium supplements (although they were in women), I’m wondering what are some other good sources of dietary calcium? I ‘ve heard you mention bone meal before which seems to have high amounts of phosphorus as well. Is there anything else you would reccomend?


  9. Hi,
    does high level of phosphorus in blood test , relevant with anemia? and does calcium level play any role here ?

    1. Hi Narsis,

      If you have anemia, I would be surprised if calcium and phosphorus balance was a major determinant. You need your medical practitioner to run blood tests to determine the specific cause of the anemia and address that.


    1. Hi Jim,

      Not at the moment. In the future, I may offer them as a paid version, or if the podcast can become profitable through advertising, offer them for free. At the moment I can't afford the extra investment. I do see the value though and have it in mind for the future.


  10. Chris congratulations for your work and knowledge! Very informative podcast! I have some questions, if you allow me and if you have time to reply.
    I am from Bulgaria and we have two types of cheeses: white in brine and yellow called kashkaval. Most producers use in them calcium dichloride(e509) as preservative. Can you give your opinion if that Cacl2 is bad, dangerous for the health? Is that like the manmade phosphrous?
    Do you know if there is vit k2 in kefir made with grains?
    And finally – should one supplement with vit D3 and vit k2 mk7 and what should be the optimal dosage considering that the one is not going to the beach? I am asking this because from the podcast it seems that optimal levels of vitamin d, calcium and vit k2 are crucial for the bone/ teeth health and as you said they help for relaxation of the pituary gland. It will be nice to hear your opinion for these optimal levels of the trio.

    1. Hi Evgeni,

      I haven't looked into CaCl2, but i do not think it would have the specific effects of phosphates. I prefer fewer additives when possible though.

      I haven't seen K2 data for kefir.

      Vitamin D depends on your exposure to sunshine, calcium intake, etc. I think it is best to try to be in the lower half of the reference range for PTH, and supplement if you can't do that naturally.

      For K, it is best to just eat a lot of K-rich foods. K2 supplement at ~200 mcg could be good insurance though. I take 1 mg Thorne MK-4 because I have a genetic predisposition to poor vitamin K recycling.

  11. My latest blood test results are (with the respective reference ranges shown in brackets):

    Calcium 2.47 mmol/l (2.20-2.65)
    Phosphate 0.86 mmol/l (0.81-1.45)
    PTH 23.4 pg/ml (12.0-88.0)

    These look good to me.

      1. My latest readings are:

        Calcium 2.52 mmol/l
        Phosphorus 0.81 mmol/l
        PTH 33.9 pg/ml

        So PTH and calcium have increased, and serum phosphorus has decreased, to the point of a [mild?] phosphorus deficiency.

        What’s interesting is that my serum vitamin D – that’s 25(OH)D – level has actually increased. It used to be 74.4 nmol/l (=just shy of 30 ng/ml) and now it’s 114.9 nmol/l (=46 ng/ml).

  12. What about if your blood/serum calcium is high (mine was elevated a few years ago but I haven't checked since then)? What can cause that, and what should I eat or what supplements should I take to lower the calcium to normal range? I've taken 90 mcg of Vitamin K-2 in MK7 form each day for the past year and between 5-10g of vitamin D daily (40mg/1lb body weight).

    1. Although, I don't mean to imply they can't be partly managed by diet. However, I have no intention of doing that because it is profoundly cumbersome compared to giving blood, and giving blood is both safer nutritionally and beneficial to others besides myself.

  13. Cronometer has phosphorus. However, when you pick foods, you have to choose as Source USDA or NCCDB or otherwise you do not get all the micronutrients. I have used the free version from my laptop. Sarah Ballantyne, PhD (thepaleomom) has recommended the app version several times in her podcast.

    About PTH. I will also measure it next time. Before I dig into the literature, do you know by memory and you have time to answer, why the lab recommends plasma calcium measurement and not serum calcium with PTH?


    1. Thanks Noora! I will check out chronometer at some point.

      I don't know if the plasma/serum distinction is important off the top of my head. I do know that if you are measuring ionized calcium rather than total calcium there is some cumbersome and precise methodology involved in collection, but I don't remember details off the top of my head or if they relate to the serum vs plasma distinction.

    2. Modern Nutrition in Health and Disease had great information but I do not have the book and Google Books showed naturally only patches here and there.

    3. Laboratory results:
      Phosphate 1.07 mmol/l (0.85-1.5)
      PTH 4.40 pmol/l (1.48-7.63)
      Calcium 2.21 mmol/l (2.15-2.51)

      Started Ca supplement just before going to bed as optimal Ca should be above 2.3 according to my FM MD. Even though, I get enough Ca from food there is still an absorption problem due to my history of taking PPIs 6 years during my PhD studies and post-doc.

    4. Noora,

      Please do not take anything I say as a substitute for medical advice, but it looks to me like you need to substantially increase your calcium intake or your calcium-to-phosphorus ratio over what it was leading up to these blood measurements.


  14. Thank you for the excellent article! Does your app for measuring nutrients measure boron? I don't know a whole lot about how it works, but boron is very important to the parathyroid and calcium/phosphorus metabolism. It might be a missing piece for some who can't seem to correct calcium metabolism, and I am wondering if you have any insight into this. Thanks for all your excellent information.

    1. MyFitnessPal doesn't track boron, and I wouldn't recommend it for tracking micronutrients. It's good for calories and macronutrients. I don't know of an alternative app that tracks trace minerals and has the user-friendliness of MyFitnessPal.

  15. This was all very interesting. I learned a lot! Thank you so much for explaining these complicated issues in such a good way.

    Still I find the study linking > 700 mg phosphorus/2000 kcal to increased mortality (https://www.ncbi.nlm.nih.gov/pubmed/24225358) a bit worrisome even if it probably did not properly account for the phosphate additives. But these additives can also be calcium based, like dicalcium phosphate.

    A reason why Price put such great emphasis on vitamin D may have been that the people he studied ha an improper Ca:P ratio or didn´t get enough calcium (and phosphate). I think this has been shown in canine feeding. They require very little vitamin D if the Ca:P is optimal and they obtain enough of the two minerals.

    The Gaelics and the Inuits would obtain a lot of vitamin D from seafoods (more than the Swiss), and could maybe tolerate a poorer ratio. But the Inuits have also been reported by Viljhalmur Stefansson to be short lived and look 20 years older than Europeans. So I think what´s importance is maximum lifespan, not what the body can get away with by resorting to stressful compensation mechanisms. Maybe vitamin D hormone is one such stressful process that actually taxes the kidneys; they would have to excrete more phosphate and as a result burn out quicker, so the person dies younger. A typical middle aged person would probably already have a suboptimal kidney function, and maybe it is better for him to eat white rice and potatoes rather than sourdough bread and soaked long cooked oatmeal.

    There is also the broader issue of alkalinity verus acidity and the idea that the alkaline minerals to some extent can substitute for one another. What matters is the overall load as reflected for example the potential renal acid load, talked much about by Loren Cordain. Ray Peat may be on to some things that could be way ahead of its time (https://raypeatforum.com/community/threads/alkalinity-vs-acidity-2012-kmud-the-herb-doctors.5411/). He would also put great stress on the Ca:P in weight loss and to increase metabolism, an issue that alas is very little explored: https://nutritionj.biomedcentral.com/articles/10.1186/1475-2891-12-90 https://jn.nutrition.org/content/133/1/268S.full

  16. Hey Chris! Huge fan of yours and I am loving the new podcast.

    For someone who is studying nutrition/health/fitness and is trying to stay current on the research, what would you recommend? I subscribe to several journals, but I am curious how you go about it? What journals would you recommend? Do you block off time each day to read (I did listen to your daily routine podcast, BTW)? Any other resources you would recommend (even textbooks)?


    1. Hi Tim,

      As a starting point, the latest edition of Modern Nutrition in Health and Disease, listed in the show notes.

      As a starting point beyond that, see if there is a specific textbook for a specific nutrient. The Feldman vitamin D textbook is a great resource.

      From that, I look for information on an as-needed basis. I do not try to preserve time to read. When I see things I expect to find interesting to read, I save them in an Evernote notebook. When I am researching something specific, I try to condense the related reading into as few batches as possible, with a specific Evernote notebook for the topic, taking annotations within Evernote. I do not find it useful to subscribe to specific journals. I search pubmed, and use Google Scholar as a secondary resource. I find it particularly useful to take an interesting paper from pubmed, put it in Google Scholar, and browse or search through the papers that have cited the interesting one.

      I think subscribing to a particular journal can have no effect except to create bias. I also think that if I read everything in a particular issue when it came out, it would suck up exorbitant amounts of time creating a scattered mess inside my brain, which would be counter-productive on both levels. If I were to subscribe to anything, it would be an RSS feed for certain keywords in the databases of my choice, but I have yet to find that more useful than carving out a time to exhaustively study something and doing keyword searches at that point in time.


  17. Dear Dr. Masterjohn,
    I have read and benefited from your postings over the years and have recently started listening to some of your podcasts. Your podcast on calcium, phosphorus, and PTH is a grand slam. I share some of my experience below. I am male, 66 years old and with my spouse am raising grass–fed beef in rural Maryland.

    Starting in late spring, 2013 I would have bouts of fatigue that were of a different quality from “normal” fatigue. I am used to grappling with some fairly intractable, big problems and, usually, a good nights sleep and hard days work reveals a way forward. That wasn't happening and I noticed it in matters other than farm work. "Is this what old age is like?" I wondered in disappointment.
    As the summer progressed I also found myself occasionally caught and frozen in the cross fire of conflicting internal priorities or directives. As though the normal, subconscious subordination and inhibition of multiple intentions was turned off. The net result might be an inability to do anything for an hour accompanied by the feeling of being in a foxhole under enemy artillery fire. One unskillful response I would generate would be to push some activity, any activity just to get something done and get moving. And that pushing generated pressure and worry itself.
    The feeling tone of all these was qualitatively different from the normal ups and downs of my aging existence. I knew I was aging but this seemed awfully severe. I began to doubt we could continue with cattle at all. I also wondered how off-kilter I was going. Is this how Alzheimer's begins?
    With my wife's strong encouragement, I decided to see if there was any underlying physical basis by having a physical checkup. It couldn't hurt and the mere act of going was in itself a marker for me that something needed exploring NOW. I hadn't had a check up for 6 -7 years and until the Winter of 2013 had felt in the best health of my life. My Doctor ordered blood tests and I came back with elevated serum calcium. Kidneys and liver tests and thyroid all fine. She ordered another calcium test and a PTH (parathyroidhormone) test, which came back elevated. No signs of cancer or liver problems plus elevated PTH and serum calcium is a 95% accurate diagnosis for hyperparathyroidism.
    I had a nuclear medicine sestimibi protein test and a parathyroid sonogram. Both indicated an enlarged upper left parathyroid gland. After much research and finding an excellent surgeon at Johns Hopkins, I decided to act quickly. As a side note, I am normally treatment-averse.

    They took my PTH levels going into the operating room – 83 pg/ml. After cutting my neck open, the surgeon observed the very enlarged parathyroid gland and removed it. While still under general anesthetic, they took my PTH levels again. They had dropped to 18 pg/ml, which is in the lower range of normal PTH. That's a drop of >78%. The surgeon observed the lower left parathyroid gland, which was normal size and glued me up. The normal parathyroid gland weighs 20 -30 mg. A milligram is one thousandth of gram. The removed parathyroid gland was weighed at 2.88 gm, i.e. over 100 times normal mass. It was not malignant.
    The whole long experience has given me much to reflect on concerning mind-body issues and base-surface consciousness.
    My calcium and PTH levels were measured the following March and the following December and both are in normal ranges.
    After listening to your podcast I looked up my serum phosphorus and serum vitamin D3 levels before and after the surgery. All were in the normal range.
    So, I agree with you that one should "consult" with the "expert" PTH gland concerning calcium and phosphorus….. and also to determine in the "expert" has gone off his rocker.

    1. Wow Tom, thanks for sharing your story!

      Yes in this case you had a genuine problem with the parathyroid gland. The reference ranges are useful to diagnose that. I was focusing on the more common variation within the reference range where the measurement still provides actionable information when the expert has its head on straight.

      1. I realize this is more than two years later, but may be we can try to get to the root of my health and many others root health problems! What relationship does boron have in all this talk about the parathyroid, PTH, calcium, phophorus, etc with possible hyperparathyroidism? I’ve heard that boron deficiency is a cause of begnin hyperparathyroidism? I don’t want nor can I afford to go through surgery and likely redo of surgery from having to go to an inexperienced parathyroid surgeon, and I’m affraid I’m going to die (from mere kidney stones and high serum calcium ??) at only 34 years old. Four doctors through my own wallet and now Medicaid, and I still don’t have any answers on what I have which all started with scrotal pain four months ago! I believe it’s hyperparathyroidism but no proof other than “moans, groan, bones and stones…” Could glandulars help (heal) with possible Hyperparathyroidism whether benign or malignant?

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