Health Topics

  1. #
  2. A
  3. B
  4. C
  5. D
  6. E
  7. F
  8. G
  9. H
  10. I
  11. J
  12. K
  13. L
  14. M
  15. N
  16. O
  17. P
  18. Q
  19. R
  20. S
  21. T
  22. U
  23. V
  24. W
  25. X
  26. Y
  27. Z
Browse All Topics

How the Institute of Medicine Arrived at Their Vitamin D Recommendation

The latest revision of the official vitamin D recommendations were based on the body’s reaction to protect bone health, but what about the other three dozen affected organs?

December 13, 2011 |
GD Star Rating


Supplementary Info

Sources Cited



There are many ways to arrive at a target vitamin level. We’ve already examined some of the problems inherent to just using deficiency disease prevention and evolutionary arguments to establish an optimum intake. If a vitamin only does one thing, then it’s easy, you set the level at whatever the body needs to do one thing best, but what if the vitamin affects dozens of different organs, then it’s more difficult. Here's a list of the target tissues affected by vitamin D. In revising their recommendations, the Institute of Medicine decided to only look at one tissue, bone, which many considered to be a mistake. 
I did like how they went about it, though. They asked the expert: the human body. When our body senses we don’t have enough active vitamin D for adequate bone health it releases a hormone, called PTH, to boost our levels. And so the Institute of Medicine figured why don’t we just listen in on the body’s own innate wisdom and find out which level of vitamn D it feels comfortable with for bone health. And that number is about 20 ng/ml, here as 50 nanomole per liter. Once we fall below that our body is like uh, oh, and starts producing this PTH to protect our bones from softening. But that’s just the bone; what about the other 3 dozen organs affected by vitamin D?

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.

To help out on the site please email

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 seventh video in a nine day series on vitamin D. Be sure to check out yesterday's video-of-the-day The difficulty of arriving at a vitamin D recommendation.

For additional context check out my associated blog posts: Vitamin 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 seventh video in a nine day series on vitamin D. Be sure to check out yesterday’s video-of-the-day The difficulty of arriving at a vitamin D recommendation.

  • paul3917

    In the list of tissues involved with vitamin D, there’s something called the eggshell gland. What’s that? Do humans have this eggshell gland or is it found in birds only?

    • Michael Greger M.D.

      Good eye! That’s just in birds and some fish and reptiles (though presumably in platypuses as well?). It’s part of their oviducts that forms the eggshells.

  • murtaza

    hello, can u let me knw wat are the effects of vit D deficiency in adults..and wat if the level is below 5 ng/ml..?

  • DrDons

    The effects of Vit D deficiency are many as you can see from the list on the right side of this video’s diagram. It is always difficult to say which effects occur in an individual. However a level of 5 ng/ml would be considered deficient by any recommendations. For further discussion see: The best way to keep our vitamin D levels at the appropriate level is to get adequate sunlight see: For individuals with very low levels as you mention I would recommend working with a physician to get recommendations and appropriate followup.

  • ajwagner

    There was a NY Times story several days ago noting a study suggesting that CRP levels went up once blood Vitamin D levels reached 21ng/ml. ( ) Would this have any effect on your recommendations on Vitamin D supplementation?

    • JoAnn Downey

      My CRP was under 1 and my D3 level was 40ng/ml

  • Michael Greger M.D.

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

  • autumn jasmyn

    Can ;post-menopausal women take vitamin D supplements? I read somewhere that Vitamin D was not recommended for that supplementation. I would like to know the correct answer. Thank You!