Translations:Vitamin B12/8/en

Vitamin B₁₂ is the most chemically complex of all vitamins, and for humans the only vitamin that must be sourced from animal-derived foods or supplements. Only some archaea and bacteria can synthesize vitamin B₁₂. Vitamin B₁₂ deficiency is a widespread condition that is particularly prevalent in populations with low consumption of animal foods. This can be due to a variety of reasons, such as low socioeconomic status, ethical considerations, or lifestyle choices such as veganism.