Vitamin D Update

In November of 2010, the Institute of Medicine released a report, Dietary Reference Intakes for Calcium and Vitamin D. This was a long-awaited report given that in the time since their previous report from 1997, many researchers have been arguing that:

  • In addition to causing rickets and osteomalacia, vitamin D deficiency can lead to many other diseases including cancer and autoimmune diseases.
  • Optimal amounts of vitamin D in the blood are between 80 to 100 nmol/l (32 to 40 ng/ml), which was much higher than previously thought.
  • Many more people than ever before are deficient in vitamin D, especially given the higher levels thought to be optimal.

I also promoted the higher levels for vitamin D, especially given that studies published in the late 2000s on vitamin D listed categories of “insufficiency” and “deficiency” that were in line with the more recent, higher recommendations by some researchers.

But when the Institute of Medicine released their report last November, they did not agree, for the most part, with the three points above. Their Report Brief summarizes their findings (on both calcium and vitamin D):

The committee assessed more than one thousand studies and reports and listened to testimony from scientists and stakeholders before making its conclusions. It reviewed a range of health outcomes, including but not limited to cancer, cardiovascular disease and hypertension, diabetes and metabolic syndrome, falls, immune response, neuropsychological functioning, physical performance, preeclampsia, and reproductive outcomes. This thorough review found that information about the health benefits beyond bone health—benefits often reported in the media— were from studies that provided often mixed and inconclusive results and could not be considered reliable. However, a strong body of evidence from rigorous testing substantiates the importance of vitamin D and calcium in promoting bone growth and maintenance.

The IOM did increase the RDA for vitamin D from 400 IU to 600 IU for adults. But they continue to recommend ideal levels of vitamin D to be between 40 – 50 nmol/l (16 – 20 ng/ml).

I recently finished going back through many of the study summaries on the Bones, Vitamin D, and Calcium page of and adjusted them to reflect the IOM’s findings. I also added some information from other vitamin D studies, such as one on tanning beds, another on vitamin D2 vs. D3, and a 2011 report from EPIC-Oxford on vitamin D levels in vegetarians.

The good news is that many vegans who were struggling to raise their vitamin D levels to 80 nmol/l no longer need to worry about that, as 40 – 50 nmol/l is apparently fine and is the recommendation I will be promoting unless the IOM changes its recommendations in the future or there is other overwhelming evidence to do so.

This does not negate the importance of vegans making sure they get a reliable source of vitamin D. As I’ve pointed out many times, I have been contacted by many vegans whose vitamin D levels dropped well below 40 nmol/l and developed symptoms of deficiency. And even without overt symptoms (such as fatigue, or muscle or bone pain), you should not allow your bones to be harmed because you are neglecting vitamin D. My recommendations have stayed pretty much the same – if you are not getting enough sun to produce plenty of vitamin D, you should take about 1,000 IU of vitamin D per day.

9 Responses to “Vitamin D Update”

  1. Charlotte Says:

    I learned my lesson!

  2. joanne davis Says:

    Thank you, Jack, for this important information. As a Vegan, have tried sticking with
    D2 as D3 is animal based. I have been told by my acupuncturist that D2 requires higher doses. More information on this would be helpful. Again, thank you for your newsletter, and all you do with Outreach.

  3. Jack Norris RD Says:


    My recommendations are formulated to take any differences between vitamin D2 and D3 into account. For people who have not been diagnosed with vitamin D deficiency, and do not have any reason to think they have a deficiency, 1,000 IU per day should be ample. It is important to be consistent in taking it, unless you are definitely getting plenty of sun.

    Thank you for your kind words!

  4. Amanda Says:

    I was so tired for such a long time and I even went into a depression… I finally went to the doctor and found out I had a Vitamin D deficiency. (They said I was at 11 but I don’t know what unit it was or how severe that is?) I didn’t want to take the prescription because I knew it wouldn’t be vegan so I got one from the health food store, but it’s a daily supplement, 1000 IU… I’m starting to feel better but I know it’s probably a placebo… will this be enough or will I always be behind until I take higher doses to catch up?

    Also, I barely ever go outside because I hate heat, so I know that’s probably my main problem. But I do drink fortified soy milk every day… but that’s no good because I just read the label and it’s only 30% DV per cup, which I think is less than the vegan DV anyway?

  5. Jack Norris RD Says:


    For correcting vitamin D deficiency, I would recommend at least 2,000 IU per day for a few weeks. 30% of the Daily Value would equal 120 IU.

  6. Amanda Says:

    placebo effect* I meant, because it’s too soon for it to relieve my symptoms and I’m not even taking a high dosage

  7. Zak Says:

    Hi Jack –

    I am currently taking Vitamin D drops for a D deficiency. I am taking 10000iu per day, but my level is only 36 (up from 12, so that is good). I have read that 50 – 80 is optimal. Is Vitamin D one of those things that if you take too much, you end up lowering you levels? Any other thoughts as to why the levels are so low? My doctor is fine with it.

  8. Jack Norris RD Says:


    The Institute of Medicine consider 40 to 50 nmol/l an optimal vitamin D level. You can read more about that here:

    > Is Vitamin D one of those things that if you take too much, you end up lowering you levels?

    I’m not aware of that being a problem with vitamin D.

    > Any other thoughts as to why the levels are so low?

    It takes some people a while to raise their D levels and I am not sure why. There is a study showing it’s good to take vitamin D with food; I haven’t had a chance to blog about it yet.

  9. Mindy Says:

    Pure Formulas has a great price for Vibrant Nutraceuticals (formerly Vitashine) plant-based vitamin D-3. $10.83 for 60 soft gels, 1000IU; $15.00 for 60 soft gels, 5000IU. Free shipping, no minimum! If you spend $100, you get $10 off. If you don’t spend $100, you can get 10% off by using the code Next10 at checkout.

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