B12 Analogue in Mushrooms

(Note that I use the term “analogue” to refer to both active and inactive vitamin B12 analogues.)

There is a rumor going ’round that mushrooms are a good source of vitamin B12.

In June, a paper was published looking at the B12 analogue content of mushrooms in Australia (1). The authors used chromatography and mass spectrometry to determine whether the B12 was an active form, and they believed that it was.

The table at this link shows the B12 analogue content of the batches of each mushroom containing the most B12 and the batches containing the least. Assuming that the B12 is active analogue (an assumption that has not been confirmed by testing to see if it lowers MMA levels), it would take anywhere from 7 to 326 cups of mushrooms to meet the RDA.

As for the source of the B12, the authors were not sure, but they said:

“The high concentration of vitamin B12 in peel suggests that it was not synthesized within the mushrooms but was either absorbed directly from the compost or synthesized by bacteria on the mushroom surface. The latter is more likely because mushrooms have no root system to take up the vitamin in the compost as is the case with the uptake of vitamins by root plants from the soil containing fertilizers.”

The take home message: As with anything that has fecal contamination, these mushrooms might be a source of tiny amounts of vitamin B12. For many reasons, vegans should not rely on mushrooms for their B12.


1. Koyyalamudi SR, Jeong SC, Cho KY, Pang G. Vitamin B12 is the active corrinoid produced in cultivated white button mushrooms (Agaricus bisporus). J Agric Food Chem. 2009 Jul 22;57(14):6327-33. PubMed PMID: 19552428.

10 Responses to “B12 Analogue in Mushrooms”

  1. Jason Says:

    This is such a breathe of fresh air. It’s always nice to hear from someone who doesn’t buy into the propaganda about B12. I’m pretty sick of other vegans telling me I can get B12 from not washing produce. I’d wish they come read your stuff. Keep up the good work!

  2. Julie Says:

    Thanks for the info Jack! I hadn’t heard about B12 in mushrooms until reading this. Like Jason, above, I have heard a number of vegans telling others not to wash their produce! I had read recently about B12 analogues in algae and how they probably cannot be used in our bodies- I haven’t done the research on it yet but if you know more about it, I’d love to hear!

    Sincerely,
    Julie

  3. Jack Norris RD Says:

    Julie,

    This article takes a look at B12 analogue amounts in algae and seaweed:

    http://www.veganhealth.org/b12/plant

  4. Justine Butler Says:

    Good article! At the Vegetarian & Vegan Foundation, we regularly get asked about spurious B12 sources (sea vegetables, mushrooms and even apricots!). We have published a fact sheet about B12 that may be helpful: http://www.vegetarian.org.uk/factsheets/b12factsheet.html

  5. Butterflies Says:

    HI there,

    I used to sell mushrooms and they are often grown in chicken manure…I wonder if the B12 is from the poop they are grown in? Seems likely.

  6. Gorilla Says:

    http://www.ncbi.nlm.nih.gov/pubmed/19552428

    J Agric Food Chem. 2009 Jul 22;57(14):6327-33.
    Vitamin B12 is the active corrinoid produced in cultivated white button mushrooms (Agaricus bisporus).
    Koyyalamudi SR, Jeong SC, Cho KY, Pang G.

    ” HPLC and mass spectrometry showed vitamin B(12) retention time and mass spectra identical to those of the standard vitamin B(12) and those of food products including beef, beef liver, salmon, egg, and milk but not of the pseudovitamin B(12), an inactive corrinoid in humans.”

    Dear Jake, i think this bio-available, in the same form as Vitamin B12 in meat, liver, fish, eggs and milk.

  7. Jack Norris RD Says:

    Gorilla,

    My analysis of that paper here:

    http://veganhealth.org/b12/plant#mush

    In short, I would not rely on mushrooms for vitamin B12.

  8. John Says:

    I genuinely believe that we’re evolving away form eating meat because:
    a) it’s more efficient; up to ten times more
    b) we’re accepting animals as other lifeforms that have emotions and being
    c) food is going to get smaller and smaller until it’s molecular – for control

    Whether we HAD to eat meat in the past or not is beside the point. We now have the option in this modern world to arm ourselves and begin the long evolutionary move away from being conventional earth-based predators.

    Our world is no longer natural. We cannot reliably make comparisons with the past. We must move forward. We have to use a blend of naturalism and technology to begin the transformation. We cannot live in the past!

    Being an educated Vegan is really the only way to be a Vegan.

  9. James A. Randle Says:

    “As with anything that has fecal contamination, these mushrooms might be a source of tiny amounts of vitamin B12. For many reasons, vegans should not rely on mushrooms for their B12.”

    Yeah right, I’m a vegetarian too and i don’t have any idea where to get my vitamin b12. My doctor friend recommend this mouth spray (http://products.mercola.com/vitamin-b12-spray/), what’s your opinion on this?

  10. Jack Norris RD Says:

    James,

    It’s probably fine. It’s easy enough to get from fortified foods and multivitamins or supplements that you should easily be able to find at any grocery store.

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