Vitamin B12 in Pregnancy, Miso, and Tempeh
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.