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Vitamin D Supplements May Be Necessary

To reach the circulating (25-hydroxy) vitamin D levels associated with the lowest overall mortality, one may need to take supplements, given data suggesting suboptimal production from sun even under optimal circumstances.

December 9, 2011 |
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Supplementary Info

Sources Cited


Image thanks to Tobyotter.


How much sun exposure might one need to get their target vitamin D level to that found associated with the lowest total mortality rate? Well, it depends. It depends on our age, how long we’re exposed, the time of day, the time of year, our latitude, our skin color, our use of sunscreen, and how much of our body we’re exposing. Even in Boston, though, all it takes is 10-12 minutes, of midday, summer sun, without sunblock—if, you’re a young, pale, naked caucasion. But then you’re golden! Actually, you’d be a little pink. Note, though, if you’re some old white guy prancing around naked on the Commons you’re not going to make it.
As I’m hope you’re beginning to appreciate, it’s not easy to make one-size fits all recommendations for how much sun exposure one might need. And “Low vitamin D status despite abundant sun exposure” has been found even in the best of circumstances: young, half naked skateboarders in Honolulu, mostly caucasion, averaging 30 hours of sun a week, and 51% didn’t even make it to 30. If they can’t, who can?
And these days, even if we’re an albino nudist at the equator, how often might we be getting outside in middle of the day with a deskjob?
So, if we’re really interested in getting to the vitamin D level associated with the lowest mortality rates, and our lifestyle or latitude won’t allow us the necessary sun exposure, then one needs to take vitamin D supplements: the piddly amount added to soymilk, calfmilk, margarine or mushrooms would simply not be enough.

To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring watch the above video. This is just an approximation of the audio contributed by veganmontreal.

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Dr. Michael Greger

Doctor's Note

Please feel free to post any ask-the-doctor type questions here in the comments section and I’d be happy to try to answer them. This is the fifth video in a nine day series on vitamin D. Be sure to check out yesterday's video-of-the-dayVitamin D and mortality may be a U-shaped curve.

Also, check out my associated blog posts for additional context: Eating To Extend Our LifespanVitamin D: Shedding Some Light on the New Recommendations, and Vitamin D from Mushrooms, Sun, or Supplements? 

  • Michael Greger M.D.

    Please feel free to post any ask-the-doctor type questions here in the comments section and I’d be happy to try to answer them. This is the fifth video in a nine day series on vitamin D. Be sure to check out yesterday’s video-of-the-day Vitamin D and mortality may be a U-shaped curve.

    • Ali Canani

      Hi Doctor,
      I noticed that since I started taking Vitamin D3 supplements, I feel really itchy all over. Could that be related to the D3 supplements? The onset is usually within an hour of taking it and it takes a few hours for me to stop itching. If it is related to the D3, what are the alternatives in winter?
      Thanks for your help.

  • filippodibari

    In some European countries, Vit D supplements prescription to adults over 70 years of age, with ostheoporosis, consists of monthly dosages of 25.000 IU (=820 IU/d considering 30.5 days/mo).

    IOM Upper Level is 4000 IU/d.

    Question: any study about the possible toxicity for such a large monthly dosages?

    NB: I recall similar questioning about Vit A mega doses in large national campaigns in developing countries in the last decade.

    I could not find anything so far on PubMed for Vit D.

    Thanks Dr Greger.


  • DrDons

    Hi filippodibari, I do not think a single monthly dose of 25,000 would lead to toxicity based on information at this time. Your concern is well placed though… since we have a history of making recommendations only having to change them after finding out about toxicities later.

  • vfayes

    Dr. Greger — have you heard about the new vitamin D3 spray? What is your opinion — helpful? Harmful? Waste of money? Thanks!

    • Michael Greger M.D.

      Based on their current pricing, supplementing with that product would cost hundreds of dollars a year. Given the fact that at the preferred daily dosing D2 and D3 appear to be equivalent, I would suggest choosing a less expensive option (D2 is easily 10 times cheaper). Just think about how much kale you could buy with all the money you save!

      • JG

        im guessing from the above comment that you feel D2 is just as effective as D3?  i’m vegan and recently found out im very deficient in D.  from what i’ve read, i got the impression that D3 is more absorbable and d2 could be toxic.  I would much rather take D2 b/c of my moral concerns..but i was scared into taking D3!  what is your opinion on this matter?  thanks so much in advance.

  • Michael Greger M.D.

    For some context, please check out my associated blog post Vitamin D: Shedding Some Light on the New Recommendations!

  • Lidia Varvari

    Dear Dr. Greger,

    Thank you for this interesting video!

    Could you provide us with a list of the best oils/butters to use as a sunscreen (including a range)?

    Thank you so much!