More Clues Toward Determining Optimum Vitamin D Levels

Yesterday I got an interesting email from The Vitamin D Council reporting on a new study that measures the vitamin D levels of the Masai and Hadzabe of Africa.

It seems there’s a good amount of epidemiology for vitamin D levels in people with various illness and disease; as well, there’s epidemiology for disease incidence by latitude (as surrogate for vitamin D levels), but not really anything measuring the vitamin D levels of a a group of normal people one might expect to have reasonably high levels.

Previously, there was only a 1971 study of 8 sunbathing, white lifeguards who maintained levels in the range of 50-80 ng/ml.

So here’s the abstract of the new study:

Traditionally living populations in East Africa have a mean serum 25-hydroxyvitamin D concentration of 115 nmol/l. Luxwolda MF, Kuipers RS, Kema IP, Janneke Dijck-Brouwer DA, Muskiet FA.

Dr. John Cannell explains the study thusly:

The Maasai are no longer hunter-gatherers but live, along with their cattle, either a settled or a semi-nomadic lifestyle. They wear sparse clothes, which mainly cover their upper legs and upper body, and attempt to avoid the sun during the hottest part of the day. They eat mainly milk and meat from their cattle, although recently they began to add corn porridge to their diet. Their mean 25(OH) vitamin D level was 48 ng/ml (119 nmol/L) and ranged from 23 to 67 ng/ml.

The Hadzabe are traditional hunter-gatherers. Their diet consists of meat, occasional fish, honey, fruits, and tubers. They have no personal possessions. They wear fewer clothes than the Maasai in that the men often wear nothing above the waist. Like the Maasai, they avoid the sun during the hottest part of the day. Their mean 25(OH)D was 44 ng/ml and ranged from 28 to 68 ng/ml.

It was also reported in the study that all subjects had black skin types that require the most sun to produce robust vitamin D.

So I guess if you unpack all of that, a 25(OH)-vitamin D level of 50 ng/ml that the Vitamin D Council has recommended is right about in the sweet spot.

But there’s a few other things this suggests to me:

  1. Since these subjects have the most difficult kind of skin to stimulate D production, that levels higher than 50 and perhaps even way higher might be less of a concern than others have suggested. Perhaps it’s less of an “experiment” now in the longer term.
  2. You really need to pay attention to what I called in my book, being a “fish out of water.” These subjects were on the equator where the sun is most effective, combined with skin that’s least effective. Things get dicey with modern migration and relocation where you have very efficient D generating white skin near the equator (too much D) and the less efficient dark skin at advanced latitudes (too little D).

But it seems to me that the latter situation is the far riskier one: a darker skin person at higher latitudes, such as northern Europe, Northern areas of the US, and Canada. The white skin person can always avoid over-exposure, use some sunscreen, etc., but the dark skin person suffers a double whammy of having less efficient skin for synthesis, combined with a sun that’s only effective in stimulating vitamin D for part of the year (the higher the latitude, the less effective).

How about the health of the Masai, in general? Do I really need to answer that question? I recommend Dr. Stephan Guyenet’s series:

  1. Diet and Body Composition of the Masai
  2. Masai and Atherosclerosis
  3. More Masai
  4. Nutrition and Infectious Disease

That 4th link wasn’t actually in the series but deals with the Masai, as well as vitamins A & D, which we now know work in synergy (along with K2). Here’s an excerpt:

…However, their colleagues had previously noted marked differences in the infection rate of largely vegetarian African tribes versus their carnivorous counterparts. The following quote from Nutrition and Disease refers to two tribes which, by coincidence, Dr. Weston Price also described in Nutrition and Physical Degeneration:

“The high incidence of bronchitis, pneumonia, tropical ulcers and phthisis among the Kikuyu tribe who live on a diet mainly of cereals as compared with the low incidence of these diseases among their neighbours the Masai who live on meat, milk and raw blood (Orr and Gilks), probably has a similar or related nutritional explanation. The differences in distribution of infective disease found by these workers in the two tribes are most impressive. Thus in the cereal-eating tribe, bronchitis and pneumonia accounted for 31 per cent of all cases of sickness, tropical ulcers for 33 per cent, and phthisis for 6 per cent. The corresponding figures for the meat, milk and raw blood tribe were 4 per cent, 3 per cent and 1 per cent.”

So they set out to test the theory under controlled conditions. Their first target: puerperal sepsis. This is an infection of the uterus that occurs after childbirth. They divided 550 women into two groups: one received vitamins A and D during the last month of pregnancy, and the other received nothing. Neither group was given instructions to change diet, and neither group was given vitamins during their hospital stay. The result, quoted from Nutrition and Disease:

“The morbidity rate in the puerperium using the [British Medical Association] standard was 1.1 per cent in the vitamin group and 4.7 in the control group, a difference of 3.6 per cent which is twice the standard error (1.4), and therefore statistically significant.”

This experiment didn’t differentiate between the effects of vitamin A and D, but it did establish that fat-soluble vitamins are important for resistance to bacterial infection.

So, there appears to be a dietary factor as well, which should make perfect sense, since we evolved over millions of years outdoors, at latitudes appropriate to our skin’s ability to produce vitamin D, and we ate real foods—not nutritionally bankrupt serial grains and all the processed crap they make from them now.

Just one more thing. How about cancer? While I looked but could find no references for cancer rates in the Masai, I do have some epidemiology for various cancers by vitamin D levels as well as latitude.

It’s from this very long and complex presentation: Dose-Response of Vitamin D and a Mechanism for Prevention of Cancer (PDF). Cedric F. Garland, Dr.P.H., F.A.C.E., Edward D. Gorham, M.P.H., Ph.D., Sharif B. Mohr, M.P.H., and Frank C. Garland, Ph.D., Department of Family and Preventive Medicine
UCSD School of Medicine and Moores UCSD Cancer Center, December 2, 2008.

This first slide is a plot of renal cancer rates in males (left) and females (right).


What do you make of that? Can anyone think of anything that might explain it better, with less assumptions (Occam’s Razor style) than vitamin D?

Dose-response relationships from cohort studies were used to estimate the number and percent of cancer cases that could be prevented worldwide by vitamin D3 supplementation:

Vitamin D Level

Basically, what this estimates is that keeping your level of 25(OH) above 50 ng/ml dramatically reduces your risk of cancer.

And so now, given the above, I see no reason anyone should not be setting about to ensure it. And eat real food while you’re at it and better your chances even more.

Here’s the list of cohort studies that were used in that last graph:

  • Gorham ED, et al. Am J Prev Med. 2007;32:210-6.
  • Garland CF, et al. Am Assoc Ca Res Mtg San Diego April 14, 2008
  • Li H, et al. PLoS Med. 2007;4:103.
  • Tworoger SS, et al. Cancer Epidemiol Biomarkers Prev. 2007;16:783-8.
  • Mohr SB, et al. Prev Med. 2007;45:323-4.
  • Mohr SB, et al. Int J Cancer. 2006;119:2705-9.
  • Purdue MP, et al. Cancer Causes Control. 2007;18:989-99.
  • Lappe JM, et al. Am J Clin Nutr. 2007;85:1586-91.


  1. julianne on January 26, 2012 at 17:40

    I’ve been really hesitant to tell people to get their levels high with supplementation after my husbands experience with kidney stones and high urinary calcium when he kept his level at 50.

    Vit A, and K2 also need to be in place – and many people just don’t do this (my husband didn’t, and he is likely genetically susceptible to stones, as his father had them).

    Chris Masterjohn has written some good pieces – one just a few days ago.

    In New Zealand vit D is getting a lot of press, and what happens in people all start taking large amounts, however the vit K2 and A requirement is unknown, as it is not in the media. We all get our vit D levels high and some susceptible people get high calcium levels, and kidney stones as a result.

    In the lifeguard study – I believe there was a higher incidence of kidney stones in those with the highest levels.

    I would rather my clients keep their levels good but not very high so they don’t get into trouble with excess calcium.

    • Shameer M. on January 26, 2012 at 18:17

      If you’re taking Vitamin A & K2 along with Vitamin D, does that lower your risk of getting kidney stones?

    • Richard Nikoley on January 26, 2012 at 18:25


      Well, I guess I’d rather have kidney stones than cancer, when it comes down to it.

      But this is why I tried to emphasize a proper diet. One need not supplement A and K2 if they are eating right, and I’m for more modest supplementing of D than some of the off the chart stuff like 10K IU per day (I take 4k).

      But also, I think it signals awareness of not being so afraid of the sun. Probably a person would do great who eats a nutritionally appropriate diet and gets daily sun exposure in the spring, summer & fall—unless they’re a “fish out of water,” in which case they need to either go with less exposure (whites in equatorial regions) or supplement (darks in high latitudes).

      • Alex on January 26, 2012 at 19:17

        My recollection is that kidney stones can be avoided by simply drinking lots of water.

    • g on January 26, 2012 at 21:09


      was your husband on sufficient magnesium for repletion? my experience is that supplementation with D actually unmasks Mg (magnesium) deficiency which is just as epidemic as D deficiency!

      Zinc deficiency may also be unmasked… Zn is vital for immunity and proper immune and hormone functions… sometimes people complain of adverse rxns th vit D but It sounds typically more consistent with zinc or magnesium deficiency!!
      Mag deficiency is also a risk factor for kidney stones fyi.

      • julianne on January 27, 2012 at 13:22

        Thanks G, I agree re the magnesium,when my husband got the kidney stone, I did a bunch of research and added some supplements. There are some things he doesn’t eat e.g he is allergic to liver (gets a rash). I’ll check re zinc too.
        So he added more magnesium, LEF K2, codliver oil for vit A, lemon juice for citrate.
        This all happened about 9 months ago. He is way better now, and the hypercalciuria has reduced and the other symptoms have gone. He is all for getting his Vit D from the sun and I think he will stick to getting sun in summer and not take D supps. Since he dropped the Vit D, his levels stayed above around 45 – 50 for months.

        @Alex hubby drinks a lot of water, always has, 3 -4 litres day.

      • grace on January 28, 2012 at 08:43

        That is odd to have a liver allergy!! How curious. IS that corn-fed or soy-fed liver? These are GMO and I wonder the whacko proteins and lectins, and subsequent dysregulation they cause….

        How is his thyroid/adrenals? How is his PTH???? I’ve observed a ton of elevated PTH with vitamin D deficiency. THis makes sense and not just in the renally compromised. It is the body protecting serum mag for ~400 enzymatic, ATP and hormone pathways by sacrificing the bone matrix and degrading it into circulation… fyi PTH gets better within 6months to normal values with vitamin D and Magnesium/zinc. My sister used to get kidney stones but it was a function of probably several factors: untreated hypothyroidism, vitamin D deficiency, 3rd trimester pregnancy (that won’t apply to your hubby!!!) *haa aha!*

  2. Lute Nikoley on January 26, 2012 at 20:44

    I had kidney stones in 1987, since I started having my D level checked, it’s been in the 90’s with no side effects or kidney stones. I’ve also been taking K2 and A.

  3. Anthony on January 26, 2012 at 22:14

    Hi Richard,

    In your last article on K2 and D, you where talking about avoiding neolithic agents of disease (NAD: flour, sugar, vegetable oils) – I’m still doing a bunch of reading and trying to get on “the right path” with my eating and all.. but my “quick question, need a quick answer” is:

    Stevia. If I’m to avoid using sugar.. what about stevia? Can I use that? or is that still a “neolithic agent of disease”..? Thanks!

    • Richard Nikoley on January 26, 2012 at 22:26

      I really don’t know. What I do is simply don’t use sweeteners hardly at all. The other day, I tossed two packets of sugar in an iced tea for fun, becaue I always drink it unsweetened.

      Did you get that? I did it for fun.

      The idea that things need to be sweetened is simply foreign to me.

      So, if you feel like sweet, just got for the sugar, time to time. If you make it very intermittent it won’t be a problem. Or, if you want to be paleo about it, honey.

      But above all, try to kick the idea that anything has to be sweet to eat or drink.

      • Anthony on January 26, 2012 at 23:33

        “But above all, try to kick the idea that anything has to be sweet to eat or drink.”

        Certainly something to strive for. My current situation is that in an effort to start eating healthier, since I bought one of those ridiculously high powered blenders a while back, I’m staring my day with “green smoothies” – however even with all the fruit I’m putting in, they still taste crappy and it was a chore to get them down – and THAT means – I wouldn’t continue doing it for long.

        I was taking a handful of organic spinach and kale, and then adding organic apples, (all SUPER cheap from a local store actually) and then an assortment of frozen fruit – strawberries/mangoes/raspberries/peaches/blueberries – picking like 2 or 3 of those and blending that all up. Yes – with all that fruit it still tasted like bland vegetables. I added 2 packets of stevia to that – and WOW the difference it made – made it good, and therefore something I would CONTINUE to do.

        I’m wanting to add some protein to this and opted for some egg protein powder. Ordered and on the way.. can’t imagine it will make it taste that great without the stevia.

        Am I going about this all wrong? :(

        That’s the problem with how unhealthy we are in today’s society – it’s FAST, CHEAP and EASY to eat shitty food.

        Any tips on how to start eating better that is good for someone that is BUSY with work/on the go? Meaning – how to prepare good, fast, easily PORTABLE food? (or tips/discussion on smoothie thing?)

        Thanks man!

      • Mat on January 27, 2012 at 06:49

        I’ll jump in with a thought – if you’re putting in all that fruit and you think it tastes like ‘bland vegetables’, I’d try to completely eliminate sugar for a while – your tastebuds need to be reprogrammed. That, or you are buying some seriously bad fruit.

      • John on January 27, 2012 at 08:01


        I do think you’re doing it all wrong. The idea of spinach and kale blended with fruit sounds flat out disgusting to me. If you want to eat spinach or kale, eat spinich or kale. If you want to eat fruit, eat fruit.

        Also, these shakes are not REAL FOOD. Egg white powder is a processed food- like sugar, flour or vegetable oils (most of the egg nutrition is in the yolk anyway). I’m not saying they can’t be useful as a supplement, but I don’t think you need them, and also, it sounds like you’re using it WAY too much. Meat and eggs should be the base of your diet calorically, and also your primary source of fat and protein (and all the other mirconutrients that come with them). Keep some hard boiled eggs on hand, precook your meat for the week and store it in the fridge, hell, even precooked store bought sausages are a decent choice.

        Final thought- you don’t need to add stevia to a ribeye to make it delicious.

      • Gene on January 27, 2012 at 08:26

        “Any tips on how to start eating better that is good for someone that is BUSY with work/on the go?”

        Yes, suck it up and start cooking. I work two jobs (60+ hrs) and cook and clean for myself while still finding enough time for learning and a halfway decent social life. People love to use the “no time/too busy” excuse for anything and everything.

        Harden the fuck up. You can do it.

      • Jasen on January 30, 2012 at 10:03

        “Harden the fuck up. You can do it.”
        Good advice for anything life can throw at ya!! Hooah!!

      • Jasen on January 30, 2012 at 10:31

        You just inspired me. I was sitting here thinking about how hard it is to quit smoking. I am going to harden the fuck up and do it!
        Thanks brother

      • rob on January 27, 2012 at 09:31

        I just have some ON Gold Standard Whey Protein at the office for breakfast, can’t get any easier than that and you don’t need a blender. And the double chocolate flavor tastes pretty good.

      • Paul d on January 30, 2012 at 00:20

        I am guessing you got the idea for green smoothies from the Internet somewhere. A good eating plan is nutrient dense, calorie sparse and something you can stick to long term. If a hit of stevia makes your smoothies tasty, so be it. You know this already anyway, if the smoothies are doing you good and you feel great and energized after eating em keep at it. Move alot, get your lean muscle mass up with strength, your waist down and you will experience alot of associated health benefits. I would exercise first thing in the morning, then slam down a smoothie with protein powder. And ye, the anti-processed (no protein powder) pure paleo or else you are fucking up your health blah blah dogma brigade do NOT know better than you about your own body. Simply try your smoothies the way you like em for a while, and if they don’t work, try something new. Paul d

    • John on January 27, 2012 at 08:19

      On the artificial sweetner question in general- no one really knows. Stevia seems to be best of all of them, and may actually be beneficial, but it is still an evolutionary novel food (even more so than sugar and flour). A lot of the dangers of all the artificial sweetners have been overblown (based on research that used HUGE doses in rats), but that certainly doesn’t mean they’re benign, by any means. There are lots of anecdotal reports of people going paleo but keeping the artificial sweetners, and not losing weight. When they finally do stop using them, that’s when they start to see results. I’d say try to keep ANY sweetner use to 1-2 times a week, with zero being ideal. I’m working on dialing this in right now myself.

      • Richard Nikoley on January 27, 2012 at 08:47

        To me, the larger problem is perpetuating the idea that anything needs to be sweetened. If you want something sweet, have some fruit, the whole fruit, along with its fiber, where you chew on it.

      • Rhys on January 27, 2012 at 15:26

        Couldn’t the same thing be said for any flavoring? It seems like most people add spices and sauces to their foods. Couldn’t stevia be considered a ‘spice?’ I’m not really sure where the issue is outside of insulin issues, which are probably negated by the food you’re eating anyways.

  4. Jesrad on January 26, 2012 at 23:55

    My serum D vitamin level was measured at >163 ng/ml recently… which is over three times the 50 ng/ml level indicated here for primitive tribes. Needless to say I stopped supplementing immediately… but I’m wondering where the hepatic toxicity threshold sits and what kind of symptoms could indicate it ?

    • Count Iblis on February 4, 2012 at 06:58

      You need to be above roughly 750 nmol/l, which is 300 ng/ml before problems start to occur. See e.g. here:

      “However, even in the absence of definitive evidence to establish the responsible metabolite, the wealth of animal studies and human anecdotal reports of vitamin D intoxication indicate that plasma 25(OH)D3 is a good biomarker for toxicity, and the threshold for toxic symptoms is ≈750 nmol/L. This threshold value implies that 25(OH)D concentrations up to the currently considered upper limit of the normal range, namely 250 nmol/L, are safe and still leave a broad margin for error because values significantly higher than this value have never been associated with toxicity. “

  5. Sean on January 27, 2012 at 00:00

    Wow, the Czech Republic has the highest incidence of renal cancer by far. That’s pretty scary. I just went and gulped down a Carlson’s D3.

    I’m sure you noticed this on the renal cancer chart:

    Source: Mohr SB, Gorham ED, Garland CF, Grant WB, Garland FC. Are low ultraviolet B and high animal protein intake associated with risk of renal cancer? Int J Cancer. 2006;119:2705-9. Graphics: S. B. Mohr, M.P.H.

    Ha! Echos of the China Study.

    I looked for the original paper but couldn’t find it online. I’d say that there are a lot of factors that could be correlated with cancer here besides animal protein consumption, including high rates of smoking (especially ten years ago). The correlation with latitude seems pretty clear though.

    If light skin to adapt to high latitudes is so important, why weren’t the Eskimo selected for pale skin? Probably because their diet high in fish oil provided plenty of vit D already. But this makes me wonder why Iceland is so high? Don’t they eat a lot of fish?

    • Neal Matheson on January 27, 2012 at 00:59

      I had exactly the same thought In fact several of the countries are not where you might have thought they would be . The UK generally darker and more indoorsy (industrialised and rainy) with a generally poorer diet than many of the countries placed above it.

      • Sean on January 27, 2012 at 02:43

        It’s the animal protein!!!

        I suppose one has to be very careful of ethnographic data since there can be so many confounding variables, not to mention cherry picking. This table from this study shows very similar data to the table in the post. And seems to indicate that Asian-Americans are at a much lower risk than Whites, Blacks or Hispanics (who have very similar incidences), so there could be a genetic factor at play–or maybe they eat more oily fish or have some other cultural dissimilarity.

  6. dr. gabriella kadar on January 27, 2012 at 16:46

    Very good post, Richard.

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