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

Others develop autoimmune gastritis, in which the immune system damages stomach cells involved in producing acid and intrinsic factor, the protein needed for vitamin B12 absorption.

From Science Daily ● Jun. 25, 2026

The story of vitamin B12 is unusual because the body needs so little of it, yet the consequences of deficiency can be profound.

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

The success of liver treatment eventually led scientists to isolate the deep red compound now known as vitamin B12, or cobalamin.

From Science Daily ● Jun. 25, 2026

We are, after all, a planet where the rain contains vitamin B12!

From "The Lives of a Cell" by Lewis Thomas