vitamin B12

vitamin B₁₂

n.

A complex compound containing cobalt, found especially in liver and widely used to treat pernicious anemia. Also called antipernicious anemia factor, cobalamin, cyanocobalamin, extrinsic factor.

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vitamin B,

n a water-soluble vitamin found in animal foods such as meat, eggs, and dairy. Has been used for deficiencies (often found in vegetarians, particularly vegans) or lower levels from colchicine, metformin, phenformin, AZT, and nitrous oxide and to treat pernicious anemia and bursitis of the shoulder. No known precautions. Also called
cyanocobalamin, hydrocobalamin, or
methylcobalamin.