Animals, including humans, require vitamin B12 for their metabolism; plants do not. Neither animals nor plants can produce the vitamin; only special bacteria can. Animals absorb B12 in one of two ways: from bacteria living in their digestive system (like ruminants do, for instance), or via their food chain (like omnivores do, for instance). Although humans‘ large intestine is colonized by B12-producing bacteria, humans are not able to absorb the vitamin there; in humans, active B12 absorption happens in the small intestine alone.
A maximum of 2 µg of B12 can be actively absorbed by the human ileum per meal, and 2 µg is also the approximate daily required amount to maintain one’s B12 at a healthy level in the long run. Since a B12 deficiency can lead to serious health problems – especially, megaloblastic anemia and neurological dysfunction – EU legislation recommends a daily dose of 2.5 µg of the vitamin for adults.
Animal-based food is traditionally the major natural source of B12 for humans; more and more people, however, are reducing their consumption of animal-based products for health, ethical, and/or ecological reasons. Because of humans‘ unique absorption system and the lack of the vitamin in plant-based food, this reduced consumption of animal-based products is putting more and more people (not just vegans, but also vegetarians, and even flexitarians) at risk of developing a B12 deficiency.
There are two problems that face many vegans, vegetarians, and flexitarians who wish to consume the recommended daily dose of B12:
- The majority of consumers prefer natural vitamin sources to pills, so the idea of taking a B12 supplements is not very appealing to them.
- Conventional B12 is not allowed in organic-certified food products, because its production includes the use of harmful chemicals, and the use of genetically modified bacteria, which is not in compliance with organic-food legislation. This makes it unappealing to consumers who wish to eat organic.