I just updated VeganHealth.org’s articles on bones and homocysteine with the following:

Vitamin B12 and Bone Mineral Density

Taking vitamin B12 might also be important for bone mineral density.

A 2009 cross-sectional study of lacto-ovo vegetarian women in Slovakia found that their higher homocysteine (16.5 vs. 12.5 µmol/l; 78% vs. 45% were elevated) and lower vitamin B12 levels (246 vs. 302 pmol/l; 47% vs. 28% were deficient) were associated with significantly lower bone mineral density in the femur (1). Participants were not allowed to have been taking vitamin or mineral supplements. The researchers did not measure calcium intake or vitamin D status.

You can read more about vitamin B12 and homocysteine here.

1. Krivosikova Z, Krajcovicova-Kudlackova M, Spustova V, Stefikova K, Valachovicova M, Blazicek P, Nemcova T. The association between high plasma
homocysteine levels and lower bone mineral density in Slovak women: the impact of vegetarian diet. Eur J Nutr. 2009 Oct 7.

I just came across the following email I received last November (before I had this blog) from an old friend which I thought could be helpful:

“I ended up drifting from the vegan diet while in Taiwan because my nails were constantly breaking and my vegetarian girlfriend insisted I try eating meat again. I thought, ‘Well if a vegetarian is insisting I eat meat, maybe I should?’ Actually many other people were constantly urging me to eat meat there too, telling me I’m too thin etc. The carnivorous diet didn’t effect my health at all really, besides effecting my nails.

“I experienced immediate re-strengthening of my nails within 2 weeks of adding meat back into my diet. Tried going off meat again a few times, but nails would start breaking again.

“During this period I was against supplements for some reason, until reading Paul Pitchford’s Healing with Whole Foods and decided to try taking a B-complex and no meat. It worked! So I went veg again and have been for over a year. Guide to Cruelty Free Eating confirmed what I experientially discovered. Great that you’ll save countless more from needing to do the research and self experimentation on their own. I haven’t tried the mega doses of sublingual B yet – I’m going to try that too as I must have been quite deficient in B’s. I remember seeing somewhere that B’s are related to hair and finger nail nutrition, though I haven’t seen it recently. But taking B complex solved my nail problem.

“It’s great to have found my way back to VO. Thanks for still being here and all of the work you’ve done and are doing!”

(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.

B12 and Neural Tube Defects

An NIH news release today shows that low levels of vitamin B12 in pregnant women may increase the risk of neural tube defects. The authors conclude their paper by saying, “Our [analysis] suggests that women who start pregnancy with serum vitamin B12 concentrations below 300 [pg/ml] (221 pmol/L) are at significantly higher risk for [neural tube defects]. Improving B12 status beyond 300 [pg/ml] might offer further risk reduction but this is unclear.”

In my epic novel, Vitamin B12: Are You Getting It?, I recommend that all vegans keep their vitamin B12 levels at 350 pg/ml or higher (click here for that info, scroll to bottom of page). In order to do this, vegans should follow these recommendations.

And on this page, B12 and Chronic Disease: Homocysteine, I warn that low B12 levels could cause neural tube defects.

So, none of this is terribly new or surprising. And while the NIH news release did not mention vegans, it didn’t stop The Telegraph from writing headlines that make it sound like the study was performed on vegans and showed vegans to have higher rates of neural tube defects:

“Vegan diet increases the risk of birth defects, scientists warn
“Women who are strict vegetarians or vegans may be a greater risk of having a child with birth defects because they are likely to be deficient in vitamin B12, researchers warned.”

The study confirms that it is important for vegan women who want to get pregnant to make sure they are following vitamin B12 recommendations. Luckily, I rarely come across a pregnant vegan who does not know the importance of making sure she is getting vitamin B12.

Tempeh & Miso

In somewhat related news, I picked up a professional-looking flyer promoting veganism the other day at a local vegetarian restaurant only to read in it that miso and tempeh have vitamin B12. On the bright side, at least they mentioned vitamin B12 and suggested supplements and fortified foods. However, the mold required to produce tempeh does not produce vitamin B12, so the only way B12 would be in tempeh is if it was contaminated with B12-producing bacteria, and in most cases it won’t be. Two studies have measured the vitamin B12 content of miso and have found none. More information can be found in B12 in Tempeh, Seaweeds, Organic Produce, and Other Plant Foods.