D2 v. D3

I have added some more study summaries to the section on vitamin D2 vs. D3 in the article Bones, Vitamin D, and Calcium on the VeganHealth.org site. My conclusion has remained the same – in amounts of around 1,000 to 2,000 IU per day, vitamin D2 is as effective as vitamin D3.

Here are the new paragraphs:

Glendenning et al. (39) (2009) compared 1,000 IU of D2 vs. D3 in people with vitamin D insufficiency who had hip fractures. After three months, those who supplemented with D3 had a 31% or 52% (depending on how they were measured) greater increase in 25(OH)D levels than those supplementing with D2. However, parathyroid hormone levels did not differ between groups, leading the researchers to question whether the difference in 25(OH)D levels were of biological importance.

Gordon et al. (40) (2008), treated 40 infants and toddlers with vitamin D deficiency. Each were assigned to one of three 6-week regimens: 2,000 IU oral vitamin D2 daily, 50,000 IU vitamin D2 weekly, or 2,000 IU vitamin D3 daily. At the end of the trial, participants’ 25(OH)D levels went from an average of 42.5 to 90 nmol/l (17 to 36 ng/ml), and there were no significant differences between treatment groups.

Thatcher et al. (41) (2009) gave children with rickets one oral dose of 50,000 IU of vitamin D2 or D3. After three days, 25(OH)D levels rose from approximately 50 to 72 nmol/l (20 to 29 ng/ml) for both groups. Calcitriol levels also increased similarly in both groups (by about 70%), however, calcium absorption did not increase, leading the researchers to conclude the rickets were not caused by low vitamin D deficiency. This should not be a surprise since the baseline average level of 50 nmol/l (20 ng/ml) of 25(OH)D should be adequate to prevent rickets.

References at Bones, Vitamin D, and Calcium.

11 Responses to “D2 v. D3”

  1. Reijo Laatikainen Says:

    Thanks for update, this is such a great resource on vitamin D! Perhaps you could this study (D3 vs. D2) as well http://bit.ly/bF0ZvL ? (I could not find it on your reference list).

  2. Jack Norris RD Says:


    Biancuzzo RM, Young A, Bibuld D, Cai MH, Winter MR, Klein EK, Ameri A, Reitz R, Salameh W, Chen TC, Holick MF. Fortification of orange juice with vitamin D(2) or vitamin D(3) is as effective as an oral supplement in maintaining vitamin D status in adults. Am J Clin Nutr. 2010 Jun;91(6):1621-6. Epub 2010 Apr 28.

    The abstract doesn’t indicate that they compared D2 to D3. I will look at the study when I get a chance.

  3. Jack Norris RD Says:

    My summary of the orange juice study:

    Biancuzzo et al. (42) (2010) tested changes in 25(OH)D from a daily dose of 1,000 IU of vitamin D2 or D3 from either orange juice or supplement capsules for 11 weeks at the end of winter. The placebo group received nothing and their 25(OH)D levels decreased slightly. The average 25(OH)D levels of the other four groups (D2 from organge juice, D2 from capusles, D3 from organge juice, D3 from capsules) went up about 25 nmol/l (10 ng/ml) with no significant differences between groups.

  4. Sherylcatmom Says:

    Hi! This could be great news. QUESTION: Where can I get vitamin D2 in doses of 5,000 IU or higher? HISTORY: For 3 years, I suffered with debilitating fibromyalgia until a wonderful doc (now my PCP) thought to test my blood for vitamin D. I was frighteningly deficient. After 3 months of 50,000 IU daily, my “fibromyalgia” disappeared. Four years later, I remain pain-free on maintenance doses (5,000-10,000 IU daily), and my blood D levels are low-normal. Thanks!

  5. Jack Norris RD Says:


    I’m afraid I don’t know of any.

  6. Mark Gailmor Says:

    There’s a company who now produces a vegan, yes you heard that right, source of vitamin D3.

    Here’s the link.


  7. Jack Norris RD Says:


    I wrote Nature’s Plus on 11-29-2010 asking them about their “vegan” D3 and have not heard back. I don’t consider it a promising sign. Here was my email:

    Dear Nature’s Life,

    I run a website, VeganHealth.org and also write one of the most popular blogs regarding vegan nutrition, JackNorrisRD.com. Vitamin D is one of our most talked about topics and I recently saw that you claim to have a vegan version of vitamin D3. Because may companies have falsely claimed to be selling vitamin D3 in the past, I am wondering if you have had your D3 tested by an independent laboratory and, if so, would you be willing to share the results with me? I would also be interested to know how you produce vitamin D3 from mushrooms, especially if you add any animal products in the production process?

    If you are able to answer these questions and provide documentation to my satisfaction, I would be able to promote it to many vegans looking for a source of D3.

    Thank you,

    Jack Norris, President, Vegan Outreach

    I plan to follow up again in the future.

  8. Frank Says:

    Please let me know if you ever figured this out? Is it possible to have a vitamin D3 from mushrooms and that it definitely is vegan friendly?


  9. Jack Norris RD Says:


    I will follow up with them at some point. In the meantime, I’m pretty skeptical that it’s possible to get D3 from mushrooms.

  10. Chris Says:

    I have been on the same quest. I do not know for sure, but I think they lay the mushrooms in the sun to adsorb the D3 similar as to how the non-vegan sources use sheep wool which has D3 from the sun within it’s fibers.

  11. Jack Norris RD Says:


    The mushrooms don’t absorb vitamin D from the sun, rather the ultraviolet rays from the sun cause a chemical reaction in the mushrooms that converts a naturally occurring molecule in the mushrooms to vitamin D.

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