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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Compare meaning

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

• vitamin B12 vs. B complex

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Example Sentences

See Examples For:

vitamin B12

“Conditions such as depression, lack of sleep, a low-functioning thyroid, and vitamin B12 deficiency can lead to memory loss that mimic the early stages of dementia,” Tan writes.

From Los Angeles Times ● Sep. 23, 2026

Jack mackerel contains about half as much omega-3 and around a third as much vitamin B12 as traditional mackerel.

From BBC ● Sep. 12, 2026

According to the researchers, this is the first time biologically active vitamin B12 has been reported in Spirulina.

From Science Daily ● Aug. 30, 2026

More ambitious production scenarios could potentially supply enough vitamin B12 to meet the RDA for more than 26.5 million children aged 1-3 and more than 50 million children aged 0-6 months.

From Science Daily ● Aug. 30, 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

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