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

Compare meaning

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

• vitamin B12 vs. B complex

Example Sentences

Older adults still require adequate protein, vitamin B12, calcium and vitamin D - especially to preserve muscle mass and prevent frailty.

From Science Daily • Feb. 26, 2026

As the crops are rich in protein, carbohydrate, omega-3s, fatty-acids, and vitamin B12, Mr Haflidason believes growing microalgae this way, could help tackle global food insecurity.

From BBC • Jan. 20, 2025

Because vitamin B12 is primarily found in meat, fish, dairy and eggs, vegetarians and vegans should consider taking a vitamin B12 supplement.

From Salon • Jan. 16, 2025

According to their findings, bacteria of the Colwellia strain M166 synthesise the smaller building block for vitamin B12 and release it into the surrounding water.

From Science Daily • May 8, 2024

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

From "The Lives of a Cell" by Lewis Thomas