occurrence of vitamin b12vitamin b12 is one of

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Occurrence of vitamin B₁₂

Vitamin B₁₂ is one of the cobalamin, a group of active principles widely occurring in nature. Vitamin B₁₂ is present especially in liver, kidney, heart, brain, spleen, thymus and muscles. Larger amounts may also be detected in the intestine. In addition, considerable amounts are found  in the culture media of various Streptomyces species and also in residue of streptomycin manufacture. Foods of plant origin are essentially devoid of Vitamin B₁₂.