Translations:Vitamin B12/42/en

Natural plant and algae sources of vitamin B₁₂ include fermented plant foods such as tempeh and seaweed-derived foods such as nori and laverbread. Methylcobalamin has been identified in Chlorella vulgaris. Since only bacteria and some archea possess the genes and enzymes necessary to synthesize vitamin B₁₂, plant and algae sources all obtain the vitamin secondarily from symbiosis with various species of bacteria, or in the case of fermented plant foods, from bacterial fermentation.