As the all-OSCA Nutrition Coordinator, I study vegan nutrition (and dietary restrictions in general) SO MUCH that I feel the need to put it out there for other people to benefit from it. Today’s topic: B12.

There is a lot of misinformation floating out there about B12, and I’m really tired of hearing completely incorrect statements about it or statements like “Well I’ve been vegan for five years and I never took supplements so I’m going to be fine forever.” Wrong! Humans did not evolve to be vegan, and while dietitians often agree that a mostly plant-based diet is preferable, few people advocate a fully vegan diet because of its obvious nutritional drawbacks. We can work around this hurdle only if we are educated. We need to set a good example for future vegans and prove that veganism is completely healthy as long as you apply a little thought.

B12

Although B12 is essential for proper cell division and blood formation, humans naturally do not need very much B12 in our diets. We only need about 2.4 micrograms daily. We also store B12 in our livers for years and years, which can mean that we don’t notice when we’re not getting enough in our diets because we’re living off our stores. But it is essential to ingest enough B12 (especially for pregnant, lactating, or adolescent people), preferably in daily doses. Some studies have indicated that B12 absorption may slow with an overabundance of the vitamin, so be careful not to skip B12 doses and try to take it in small daily amounts rather than once a week. Other studies have shown that chewing B12 tablets or allowing them to dissolve under the tongue increases absorption of the vitamin. A lack of B12 can cause anemia or nervous damage.

There is no natural vegan source of B12. No, not even most nutritional yeast! The only way we vegans can get our B12 is from fortified sources and supplements. Fortified sources include the following:

  • certain soymilks
  • some meat substitutes
  • a few breakfast cereals
  • two brands of nutritional yeast (Red Star Vegetarian Support Formula or TwinLab SuperRich YeastPlus)
  • Supplements

B12 supplements contain the vitamin in the form of cyanocobalamin (the most common), or methylcobalamin or adenosylcobalamin (also known as dibencozideand coenzyme B12, and recommended for smokers who might not be able to absorb the cyanocobalamin properly). Less commonly, some supplements contain hydroxocobalamin, but these are much harder to find. B12 is produced by bacteria (not by animal or plant sources) so the supplements are generally vegan unless the manufacturer used gelatin or other animal products in the capsules. Cyanocobalamin is sensitive to light and will degrade with exposure, so keep your supplements or fortified foods in opaque containers to prevent loss of your precious B12. Concerns about the safety of cyanocobalamin with regards to cobalt and cyanide levels are mostly unfounded unless you already have chronic kidney failure or cyanide metabolism defects; even in as high a dose as 1000 micrograms daily (over 400 times the recommended daily dose), the cobalt and cyanide contributions are considered toxicologically insignificant.

And there you have it! A crash course in what vegans need to know about B12. Now go forth and do not perish.

Sources:

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

http://www.vrg.org/nutrition/b12.htm#need

http://www.vegansociety.com/lifestyle/nutrition/b12.aspx

http://books.nap.edu/openbook.php?isbn=0309065542&page=306

  1. ettrix posted this