The role, need for, amount required, and general understanding of vitamin B-12 has proved to be controversial. Here, Vegan Ireland presents an overview of the situation as we presently understand it. We have included links and references which reflect the controversy about B-12 claims in order to help readers make informed choices about this topic.

It does not take long for any discussion about veganism to get around to the issue of B-12, a water-soluble vitamin that plays a key role in everyday functions of the brain. Vitamin B-12 is also important for the functioning of the nervous system, the metabolism of cells, DNA regulation, and the creation of blood. B-12 is unique because it is stored in our bodies. It is estimated that we have about a 5-year supply in our livers..

B-12 is an important vitamin and is an essential part of a healthy human diet (it seems that no other animal suffers from the lack of it [1]). Serious health problems can arise if we do not consume – or (re-)absorb - enough. Many people who suffer from B-12 deficiencies are non-vegans, therefore, as Dr. Stephen Walsh points out,[2] «Our need for B-12 has nothing to do with a need for meat,» adding, «Ultimately all B-12, including that in meat and milk, comes from bacteria just as the B-12 in supplements and fortified foods does.»

It is often claimed that the only foods containing vitamin B-12 are animal-derived foods. However, since Vitamin B-12 is a microbe (a bacteria) produced by micro-organisms, no foods naturally contain vitamin B-12, be they animal or plant foods.

Human beings who are healthy reabsorb about 70% of the B-12 used every day and the daily requirement is very small, possibly around 2.5 micrograms, although recommendation for daily B-12 intake alter from country to country and over time. Ireland, for example, employs RDAs (recommended daily allowances) as a guide, while the EU use PRIs (population reference intake). Official Irish health guidelines have traditionally followed U.S. recommendations rather than European ones. However, the North American (and British) recommendations have lowered in recent years leading to a proposal from a working group of the Food Safety Authority of Ireland that Irish RDAs fall into line with the rest of Europe.


One issue that has recently come to light is that some forms of vitamin B-12 cannot be utilised by the human body. For example, many plant based foods such as tofu, greens, legumes, seaweed and tempeh all contain B-12 but apparently not in a usable form. Erring on the safe side, most commentators on B-12 recommend that vegans, pregnant women and the elderly [3], for example, should take a B-12 supplement. As one or two of the links provided below show, however, not everyone agrees with this.

It is suggested, often by vegan cookery writers, that the most reliable source of B-12 supplement is cyanocobalamin. For example, Jannequin Bennett [4] does this, explaining that

«The cyanide ion stabilises the vitamin until we put it in our mouths, where enzymes remove the cyanide and attach to the cobalamin. Vitamin B-12 is then escorted through the digestive tract, changing partners along the way until it reaches the small intestine where it can be absorbed.»

Bennett suggests that the “most fun source” of active B-12 is nutritional yeast that can be sprinkled onto foods such as hummus, or used in stews or vegan gravies (for example, the Multiple Sclerosis Society of Ireland use nutritional yeast in their recipe for vegan sausages.) Bennett recommends mixing it with ground almond and a little salt as a Parmesan cheese alternative, which she uses in her own “Macaroni & Cheeze” dish. There is some concern, however, because not all brands of nutritional yeast contain an active form of vitamin B-12. As ever with the B-12 issue, little is straightforward

Vegan Ireland make no claim that our discussion of vitamin B-12 is definitive. Given that some health experts and commentators suggest that a substantial proportion of the human population, particularly pregnant women and the elderly, could be experiencing vitamin B-12 deficiencies, largely due to absorption problems, we recommend that individuals think critically about the information they receive about B-12 and frequently try to update their knowledge about the issue.