Vitamin D: Loose Ends

Okay, I’ll admit it. I may have spoken out of turn a couple week’s ago when I tried to completely cover vitamin D in a mere three posts (Deconstructing Vitamin D, Vitamin D: Sun Exposure, Supplementation and Doses, Vitamin D: Confounding Factors). A bunch of questions popped up in the comment boards – so here’s my attempt to tie up the loose ends and cover any further wrinkles in the vitamin D story.

Living in Los Angeles, I am lucky enough to be able to get much of my Vitamin D from sunlight all year round. I still take an oral D3 supplement when I’m traveling, too busy to spend much time outside, feel a sniffle coming on, etc. I take 4-10k IU D3 from Carlson’s drops (2k IU per drop). I prefer to get my D3 from the sun, however. It is not what I know I’m missing that concerns me, but what I don’t know that I may be missing. Sunlight may yield other health benefits beyond just Vitamin D production. Oral dosing with D3 won’t give you these other possible benefits.

And I’ve also noticed that switching from a SAD to a primal diet has dramatically improved my sun tolerance (and put a metabolic disorder–porphyria–into remission.

You know, I think you’re definitely onto something here. Another commenter noted a study showing an independent benefit to sunlight exposure in animal models of multiple sclerosis. Sunlight exposure improved outcomes without appreciable increases in vitamin D, or at least not enough to explain the benefits entirely. That’s just a single type of a certain disease, and it’s just an animal model, but it displays a definite benefit to sunlight independent of vitamin D. There may be even more that we just don’t know about.

Besides, there are the benefits exclusive to sunlight of which we’re already aware: warmth, barbecues, gradual tans, and simply being outside and enjoying life. It’s pretty tough to do that holed up indoors, even if you’re pounding the vitamin D caps religiously. They’ll never replace a grueling workout under the sun, or a quick sprint session along the coast on a bright day.

also, it it worth noting that according to the literature, a small percentage of people seem to react unusually sensitive to vit D supplementation. those people will show an unexpected rise of the blood calcium levels together with the D supplementation. for this, it is recommendable to also measure the calcium level before and during supplementation, to be sure to exclude even the slightest risk of overdosing.

Absolutely. If you suffer from hyperparathyroidism, check with your doctor before supplementing with vitamin D. The condition can often be exacerbated or even caused by vitamin D deficiency, but it can also result in hypersensitivity to vitamin D or over-conversion into the active form. Monitor your calcium levels, too, to make sure you aren’t over-converting D. Excessive levels of active D will generally result in higher serum levels of calcium.

Mark, thanks for the informative article. However, when publishing a chart such as the “big benefits” chart, it would be much more persuasive if you gave a reference in the scientific literature to substantiate the data. The data is, after all, very quantitative. Please provide a reference. Thanks. (And, by the way, just to stipulate, I am not a primal routine skeptic. I’ve been on a primal routine now for 2 months. But I am a health care professional, and need data confirmation.) Thanks.

Sure thing. I pulled the graph from this PDF on Grass Roots Health. It comes with the references and explanations for the “X”s (“reasonable extrapolations” from existing data). Hope it helps.

Then about a month ago I was on a site and listening to an audio interview of a doctor who said that higher glutathione levels gave protection against sunburn. Boy did my ears perk up. Unfortunately it was just a side comment so he did not elaborate. (For those who don’t know, and I was one of them, glutathione is an antioxidant produced in almost every cell in the body.) However he did say that when people switch to a healthier diet that their glutathione levels tend to go up.

That’s all I know about that for what it’s worth. I thought it was pretty interesting though.

There is a bit of literature on glutathione and sunburn indicating some potential photoprotective benefits to glutathione. In hairless mice exposed to moderate levels of UVB, those with depleted glutathione levels in their epidermis saw more sunburn than those mice with normal glutathione levels. Interestingly, there were no significant differences between the two groups when exposed to high levels of UVB. In another hairless mice study by the same authors, oral glutathione supplementation increased skin glutathione levels and reduced sunburn cell development in mice exposed to UVB.

According to the Vitamin D Council, vitamin D increases glutathione concentrations in the body. This is a likely explanation for the widely reported photoprotective effects of vitamin D supplements.

What would you suggest for people who tan to start, but burn with too much exposure to the sun, in regards to sun screen? In the summer months I’m outside constantly during the day, and while I get a nice base tan, I also will burn without sunscreen after about 45 minutes.

That’s pretty standard for light skinned people, even those with a good tan or plenty of sun exposure experience. Forty five minutes is generally plenty of time to generate your vitamin D allotment for the day, so I wouldn’t worry about the burning – that’s just a natural indication to get out of the sun and into shade! The best sun screen is shade or clothes, of course, but you could also try increasing your vitamin D levels (see the previous section on photoprotective glutathione levels rising with vitamin D levels). If you insist on opting for actual sunblocks or creams, check out a mineral sunscreen. Zinc oxide protects from both UVB and UVA, and I believe there are some clear versions available. Otherwise, make sure the block you’re using blocks both UVA and UVB. Also watch out for sunscreens that employ the vitamin A derivative retinyl palmitate, which is photomutagenic when exposed to UVA in mouse lymphoma cells.

Whatever you do, don’t rely on sunscreen all the time. Listen to your skin and get out (or in) when you start to burn, because that’s usually plenty of time for vitamin D production.

A little off topic here. I told a friend (I call him a vampire) who never goes in the sun (and when he does he is white from the sunscreen) and eats grains that his brittle bones are going to snap in half at the age of 40…..too harsh? His father just had a hip replacement at 60 years old. He avoids the sun also….coincidence? I THINK NOT!

I can’t say for sure, of course, but vitamin D supplementation has been shown to reduce osteoporosis and falls in older folks, especially the really bad falls that result in bone breaks and hip replacements. Age forty and onward is when our lifestyle really begins to catch up with us. We can usually get away with a bit of vitamin D deficiency, a lack of resistance training, and poor dietary practices for the years of invincible youth, but not once we hit forty or so. Then, all bets are off, and we’d better get our intakes in order. And if your buddy is eating as many grains as most grain eaters do? He’s going to need even more vitamin D than usual.

Keep on him about it, because he’s your friend and you care and it’s serious, but use a bit of tact. People can be fragile and defensive about diet and sunlight. Kid gloves may be warranted.

Other stuff of interest:

Dr. Kurt Harris has a nice series on vitamin D: here, here, and here.

Primal Muse has some great stuff on vitamin D, sunscreen, and sunlight.

Ned over at Health Correlator also has some good ones: here and here.

Rather esoteric ruminations on vitamin D courtesy of Peter from Hyperlipid (but then again, that’s partly why he’s so great): here and here.

One reader sent in a link to a simpler vitamin D calculator.

Thanks for reading, everyone. Now get outside and get a little sun!

TAGS:  prevention

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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44 thoughts on “Vitamin D: Loose Ends”

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  1. You’re missing out on the connection between linoleic acid and sunburn. Stephen Guyenet’s Whole Health Source blog has covered this topic (I tried posting a link last time, but it never got approved).

    The amount of linoleic acid (Omega-6) and Omega-3 in the diet controls how fast you burn in animals, and also correlates with melanoma in humans.

    This is a key point, and a key benefit of the Primal Blueprint.

    Advising people to get more sun without addressing this issue first is a recipe for a violent sunburn. 😉

  2. I just heard on Super Human Radio last week that vitamin D is also a pre-cursor to testosterone production in males. I don’t know all the science behind that but I’ll take more test anyway I can get it!

  3. Any thoughts on tanning beds, Mark? They good, bad, just ok?

    Done some of my own research but I would like to hear your opinion on it.

  4. A lot of great info, Mark, in all of your Vitamin D posts. I can’t believe how noticeable a difference I felt when I started supplementing with Vit D over the winter. Whether it was placebo effect or not, I suffer from too much darkness here in upstate NY during the winter and I find that, and getting outside helps a lot. I even tell my clients to get outside, no matter what season, for at least 10 minutes a day several times per week and they will feel a ton better too.

  5. Coconut oil works as a sun protector, extra virgin, rub in a light layer, smells wonderful and no stinging face. Very good for your skin. You will turn pink but will either fade away the next day or turn into a golden brown….try it and see.

    1. I may just give this one a go Susan. Over the past few years, I have found so many uses for coconut oil, from cooking to moisturising, so why not sun protection too – it seems to be a perfect natural product.

    2. Hello, I like coconut oil but mine has almost no smell. How can this be?. I read that coconut oil has tocotrienols which are very good antioxidants and they are absorbed through the skin, sorry I lost the link. I like it as as skin moisturizer where most creams fail.

      Unfortunately I can only spend 5 min in the sun according to

    3. Thanks for the tip! I’ve also been rubbing coconut oil on my skin prior to and after going out in the sun. I’ve developed a nice tan on most of my body and no burn! And I smell delicious, if I do say so myself. 😉

  6. I vaguely recall in an episode of Man vs Wild that Bear used coconut pulp as a natural sunscreen. In another episode, I think he pulled up some kind of shelled sea creature and used a goop that it produced as a natural sunscreen.

    Anyone else recall these episodes? Or tried, at least, the coconut pulp method?

    1. Yeah I remember that episode!! Apparently using coconut oil for sun protection has been around for awhile. Funny that no one knows about it!!

  7. I am a chinese living in central europe. So i think that i am deficient in vitamin D.

    Does a full spectrum light bulb help your body to produce vitamin D?

    PS:does anyone know how to make your bones bigger? I am a male with skinnier bones than girls. Gaining muscles is awesome but because of my skinny bones i can´t go overboard. Very skinny wrist looks weird if i had very big hands.

  8. Mark,

    A little off topic, but your comment concerning those “unusually sensitive to vit D supplementation” caught my attention. I am one of those people, only it isn’t just D, it’s essentially all supplements. They leave me in a virtual fog for days and I’ve never understood why. I’ve tried all different types and sources with essentially the same results. The list includes mineral and essentially all vitamin supps.

    With the exception of CLA and chromium I’ve never found any supps that didn’t have this effect. Any ideas?

    A google search indicates I’m not alone, but no one seems to know why.


    1. Maybe a sensitivity to binders or colorants? How about medications? Do you take supplements with or without food?

      1. “…With or without food” doesn’t seem to make any difference. I’ve even tried the D3 that dissolves in food/liquids and it has the same effect. It leaves me so tired I can barely function. If I suupliments at night I can barely get out of bed the next morning. Some meds have a similar effect, but mosttly those that report that side effect. I’ve can take antibiotics, asprin/tylenol, PPI’s etc. with no problem.

        Mostly just suppliments seem to be the problem. I haven’t been on any meds for some time now, though;stricly primal for over a year and low carb prior to that. Reasonably good shape for 57, low body fat, and no health issues to speak of.


    2. I’m the same way, I think. i never noticed the benefits of supplementation everyone else experiences…At 8000-10,000 iu of D a day for 1½ years now, things have gotten worse across the board, so I’ve stopped and am going to get My D, calcium, magnesium levels checked. Excessive Calcium in the blood sounds scary.

  9. More reasons to spend time in the sun. Also, another article to share with my dad who forced sunscreen on his 4 kids for years. 🙂 I know better now!

  10. Dr. Michael Eades ( reviewed a book called The Vitamin D Solution by Dr. Micheal F. Holick. Dr. Eades rates the book highly so I bought it myself (I got it at, using their Kindle for PCs version). Holick has based his career upon studying Vitamin D, actually a hormone. One heck of a good read. Holick links Vitamin D deficiency to many of our modern maladies.

  11. A bit unrelated, but I was wondering if any Canadians have received their Cookbook yet? I’m loving the recipes on the site – can’t wait for more!

    1. Karen, I received mine on Friday June 11th; I was told it’s been shipped on May 21st, but the package stated May 31st; I assume, it was a typo in the reply I got from the support.

  12. I know you’re supposed to get 15 mins a day but does it matter where on your body you sun? If I put sunscreen on my face, but not my legs, will I still get vitamin D?

    1. I think yes, why not?. Sun damage is cumulative, so using sunscreen in the usually exposed parts makes sense. I do as you say when I go to run. I do not like all the chemicals in sunscreens but I am sensitive to the sun.

  13. I was reading a long time ago about a scientist who invented a machine, that could see the light/colours emitted by all living things. This also included virus and bacteria. As this machine was so controversial, or even a scam, it never saw the light of day and was covered up. I can’t find anything on the web about it like I could in the past, so I don’t have any links.

    Basically what the machine did was expose viruses and bacteria to their opposite wave of light/colour and it killed the bacteria.

    I mean there’s stories and scientific proof that UV light kills germs, UV wands etc.

    So I believe why shouldn’t being in the sun do exactly the same thing for our bodies?

    I’m English and have fair skin and use to burn easily. As soon as I went low carb I was much more tolerant to the sun and even if I got sunburnt, the next day it’s like it never happened and my skin never peeled!!!

    Once you go low carb you don’t need sunscreen. Sunscreen is a scam, and only needed if you eat inflammatory grains, processed food and sugar!!

  14. I agree, Mark, Vitamin D is NOT a very easily tackled topic–there is ALWAYS more to say! I have been elongating my own series on vitamin D, which starts here:

    I always enjoy referring to your posts as resources since you have a very clearly understandable manner to your writing–thanks!

    @MaryLou I agree about the coconut oil as sunscreen. I have been trying it out after reading about a promising personal experience with it at Paleochix. Unfortunately, my fair skin still burns easily, but the coconut oil has been a terrific moisturizer and every “burn” has been minor and has turned to bronze overnight. I am going to continue the experiment, but perhaps with some zinc oxide-based sunscreen when I need to be outside for prolonged periods. I LOVE the smell of the coconut oil!

  15. “What would you suggest for people who tan to start, but burn with too much exposure to the sun, in regards to sun screen? In the summer months I’m outside constantly during the day, and while I get a nice base tan, I also will burn without sunscreen after about 45 minutes.” – “That’s pretty standard for light skinned people, even those with a good tan or plenty of sun exposure experience.”

    OK, burning in 45 minutes is not “fair” skin. I have always burned in 10-15 minutes in the summer, and I am not even ghostly white. This is what is frustrating about most sun exposure recommendations. They completely ignore those who burn in 10-15 minutes. I would be a blistered lobster in 45 minutes.

    “Whatever you do, don’t rely on sunscreen all the time. Listen to your skin and get out (or in) when you start to burn, because that’s usually plenty of time for vitamin D production.”

    Do we actually know that you make enough vitamin D by the time you start to burn, or is that advice *assuming* you can be in the sun 45 minutes without burning?

  16. The greatness of Peter at Hyperlipid that you mentioned is well captured in this gem from the second link you referenced:

    “Never forget that much of the data on vitamin D supplementation comes from a population crushed under the Food Pyramid or its derivatives, an eating plan which almost seems to have been designed to maximise disease. Vitamin D might well help under these situations, but what of those of us who eat Food? It seems like humans can get away with vegetarianism in the tropics. Move north and you need to eat meat.”

  17. Aw hell, man. I had a parathyroidectomy, and now I find out that it could be because I was trying to avoid the familial skin cancer.

    1. Pleeeeeeeeeeease do not tell me the way they decided if grain-fed or grass-fed was better was by looking at LDL and HDL?! How about looking at something that actually means something (e.g. CRP, omega-3 index, fasting insulin, ESR, plasma viscosity, etc). That is just silly and way outdated, but then again I’m not surprised when I look at who funded the study!!!!! Hey, this is an idea for a post: “Lab tests that really matter.” How many readers are using,, or other independent labs?

  18. Hi Mark, Thanks for starting today’s blog with my previous comment. As other commenter’s have pointed out, Mike Eades has reviewed The Vitamin D Solution on his most recent blog post. Here’s a relevant quote I’ve been waiting for about the additional benefits of sun exposure over Vit. D supplement. I’ll have to pick up the book to see what the other “photoproducts” are.

    “Why not just take the supplements and forget about the sun?

    “” Vitamin D made in the skin lasts at least twice as long in the blood as vitamin D ingested from the diet. When you are exposed to sunlight, you make not only vitamin D but also at least five and up to ten additional photoproducts that you would never get from dietary sources or from a supplement.””

    Old Mother Nature is pretty parsimonious with her creations, and I suspect she wouldn’t have five to ten photoproducts circulating around if they didn’t do something good for us. Just because we aren’t advanced enough yet to figure out what it is they do, doesn’t mean they don’t do something. Thus Dr. Holick’s recommendation to hit the sun if at all possible instead of the supplement bottle.”

  19. I’ve been reading all the comments and questions about Vit. D and thought I’d post this link for a wealth of current data on Vit. D:
    There is so much in fo out there I thought it would be helpful. You can cross referencece by disease conditions too which is pretty cool.

    Full discloser – I work here, but the info is great and free. So are the monthly webinars.

  20. Nice overview. We are adding 200 pages of vitamin D information every month at the Vitamin D Wiki. The Wiki includes overviews, summaries, details on Random Controlled trails, list of 500+ Clinical trials on vitamin D, and lots lots more.

  21. Who gets to write history?

    Why are Europeans white?

    Since these were written research has cast doubt of the idea that low vitamin D is result of a lack of skin synthesis or that sunbathing or popping pills will improve health. Vitamin D deficiency linked to genetic polymorphisms Vitamin D Status is Not Associated with Risk for Less Common Cancers

    And Freedman et al (2010) has found a positive relationship between calcified plaque in large arteries ( a measure of atherosclerosis or “hardening of the arteries,”) and circulating vitamin D levels has been found, higher circulating levels of vitamin D in blacks were associated with more calcium in the artery walls,” .

    1. What is your practical approach Lere?

      I am white and sensitive to sun, but moderate exposure makes me feel better.

  22. I just finished my ride across Britain – we had variable weather (well it is a British Summer!) but during the very hot days I noticed a significant decrease in burning compared with pre-Primal days to the extent that on the final day, when I was trying to nurse my clubmate home I completely forgot to apply sunscreen – I was out for 8 hours and the temperature was around the mid 20s and I was pink but no more – in days gone by I would have had first degree burns and required hospital admission had I been so remiss. if anyone is interested in how Primal eating worked on this mega trip.

  23. I have a friend with MS who says sun exposure makes her ill. I’ve read that lack of sun exposure increases the chances of MS (as well as cancer of course). Is it possible that once you have MS you can’t tolerate sunlight?

  24. Dear Dail. App.:. Vitamins are scientific products. Science forgot to grow food when Napoleon conquered vacuum tin cans for his legionares. The N.F.L. gotta rediscover the stunnig health benifits of V. K-2.

  25. Hey Mark.
    Is vitamin D supplementation only useful if you take the supplement with a meal containing fat? I say that because vitamin D is a fat soluble vitamin…

  26. Fungi have the ability to demethylate ergosterol into pure vitamin D faster than humans do! Leaving out a mushroom in the sun for a few minutes with the gills up and exposed to UV will cause a massive demethylation reaction and produce loads of vitamin D!