vitamin B12

American  

noun

1. a deep-red crystalline, water-soluble solid, C 63 H 88 N 14 O 14 PCo, obtained from liver, milk, eggs, fish, oysters, and clams: a deficiency causes pernicious anemia and disorders of the nervous system.

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vitamin B12 British  

noun

1. another name for cyanocobalamin

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vitamin B12 Scientific  

1. A water-soluble, complex organic compound containing cobalt, found especially in meat, liver, eggs, milk, and milk products. Vitamin B ₁₂ is necessary for the synthesis of DNA by the body, for the production of blood cells, and for maintaining the health of nerves. A deficiency of vitamin B ₁₂ in the diet results in pernicious anemia.

2. Also called cobalamin cyanocobalamin

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Etymology

Origin of vitamin B12

First recorded in 1945–50

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How does vitamin-b12 compare to similar and commonly confused words? Explore the most common comparisons:

• vitamin B12 vs. B complex

Example Sentences

See Examples For:

vitamin B12

Without enough vitamin B12, the bone marrow cannot produce healthy red blood cells.

From Science Daily ● Jun. 25, 2026

These findings do not mean vitamin B12 supplements can reverse ageing or act as an energy booster for people whose B12 levels are already normal.

From Science Daily ● Jun. 25, 2026

This mitochondrial role has attracted growing interest from researchers studying ageing, muscle function and vitamin B12 status.

From Science Daily ● Jun. 25, 2026

Pernicious anemia is different: the problem is not bleeding, but poor absorption of vitamin B12.

From Science Daily ● Jun. 25, 2026

If the tapeworm attaches to the right place in the gut, it can leech vitamin B12 from the victim, instigating a lethal form of anemia.

From "1491" by Charles C. Mann