How prevalent is vitamin B(12) deficiency among vegetarians?


Pawlak R, Parrott SJ, Raj S, Cullum-Dugan D, Lucus D.

Year Published: 



Nutr Rev.


Study Design: 


Vegetarians are at risk for vitamin B(12) (B12) deficiency due to suboptimal intake. The goal of the present literature review was to assess the rate of B12 depletion and deficiency among vegetarians and vegans. Using a PubMed search to identify relevant publications, 18 articles were found that reported B12 deficiency rates from studies that identified deficiency by measuring methylmalonic acid, holo-transcobalamin II, or both. The deficiency rates reported for specific populations were as follows: 62% among pregnant women, between 25% and almost 86% among children, 21-41% among adolescents, and 11-90% among the elderly. Higher rates of deficiency were reported among vegans compared with vegetarians and among individuals who had adhered to a vegetarian diet since birth compared with those who had adopted such a diet later in life. The main finding of this review is that vegetarians develop B12 depletion or deficiency regardless of demographic characteristics, place of residency, age, or type of vegetarian diet. Vegetarians should thus take preventive measures to ensure adequate intake of this vitamin, including regular consumption of supplements containing B12.


Food Sources

atm28vacations's picture

I've heard that nutritional yeast has sufficient B12. If that is the only source I'm consuming (about 1Tablespoon per day) is that enough? 

Re: Food Sources

The question of B12 supplementation is a common one, and we do have some information posted here: , which includes a link to Dr. McDougall's newsletter article on B12, a very complete history and general set of recommendations.

The most objective measure of your B12 level is to have your physician do bloodwork, which will allow you to check a number of other nutrients at the same time. Most physicians are happy to do this, especially if you explain to them that you eat a plant-based diet.

Most nutritional yeast is fortified with B12, you are right, so if you consume that regularly it is likely that you are in good shape. The best way to check though, is to do the bloodwork.