Vitamin D2 in Mushrooms

Two bits of vitamin D2 news:

1. Vesanto Melina, author of Becoming Vegan, kindly passed on a study about vitamin D2 in UV-irradiated mushrooms. 28,000 IU of vitamin D2 was fed to subjects either in the form of a supplement or from mushrooms, one time per week for four weeks. Vitamin D levels increased from 34 to 57 nmol/l in the mushroom group, and from 29 to 58 nmol/l in the supplement group (recommended levels are 40 ā€“ 50 nmol/l). The placebo group’s vitamin D2 levels decreased over the course of the study (1).

2. Dole is now making a Portobello Mushroom Powder with the RDA of 600 IU per teaspoon. (Link)


1. Urbain P, Singler F, Ihorst G, Biesalski HK, Bertz H. Bioavailability of vitamin Dā‚‚ from UV-B-irradiated button mushrooms in healthy adults deficient in serum 25-hydroxyvitamin D: a randomized controlled trial. Eur J Clin Nutr. 2011 Aug;65(8):965-71. doi: 10.1038/ejcn.2011.53. Epub 2011 May 4. | link

5 Responses to “Vitamin D2 in Mushrooms”

  1. Edanator Says:

    Although the majority of regular sunlight falls within the visible range, it also contains significant UV radiation (think sunburn). Would the sun’s UV be enough to create D2 in mushrooms, or why not?

  2. Jack Norris RD Says:


    I don’t know what you’re getting at. The sunlight created D2 in the mushrooms used in the study. Boy, was I wrong about that. I didn’t read that part of the paper, just assuming they had used sunlight.

  3. Nadine Says:

    This is good news.

    I’ve been taking Botanica’s Vegan D2 all winter and spring and really enjoy it. It’s made from organic mushrooms and one pill has 1000iu. It’s a bit more pricey than non-vegan Vitamin D3, but I recently had my blood work done and my D levels were “optimal”. I do get a lot of sun in the summer, but in the northwest, all winter there’s none! Not sure if Botanica’s formula is available in the US though.

    Next year we are thinking of getting the D sun lamp.

  4. Edanator Says:

    I read:
    “a study about vitamin D2 in UV-irradiated mushrooms”

    and I interpreted:
    study = scientific = controlled experimental parameters = controlled UV dose + controlled UV wavelength = strong UV source in a lab + controlled exposure time

    At least that’s how I would do it. Furthermore, considering that UV sources are not very expensive it would be stupid NOT do do it this way, and experiment with different wavelengths to see which ones create D2.

    If I were to do a study with sunlight, I would use filters to select different wavelengths, measure the exposure dose, and mention the word sunlight in the title. Perhaps this is what they did? If so, they must have used filters, considering the word UV-B in the title. Why not UV-A and UV-C?

    Yes, I am a researcher myself. šŸ™‚

  5. Jack Norris RD Says:


    Okay, I see what you are asking now. Here is what the paper said:

    “To produce vitamin D2-enhanced mushrooms, they were placed completely separated from each other on a 2cm meshed grid, and each side was irradiated simultaneously with UV-B (306nm) at an irradiation dose of 1.5J/cm2 after 25min at ambient temperature (22 1C). The custom-made UV unit was equipped with 8 UV-B lamps 176cm in length (UV21, Waldmann, Villingen-Schwenningen, Germany). The total irradiation area was 0.72 m2 with a homogeneous intensity of UV-B.”

    I don’t know the answer to your question.

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