vitamin B₁₂

noun

-ˈbē-ˈtwelv 

1

: a complex cobalt-containing compound C₆₃H₈₈CoN₁₄O₁₄P that occurs especially in liver, is essential to normal blood formation, neural function, and growth, and is used especially in treating pernicious and related anemias and in animal feed as a growth factor

called also cyanocobalamin

2

: any of several compounds similar to vitamin B₁₂ in action but having different chemistry

Examples of vitamin B₁₂ in a Sentence

Recent Examples on the Web

The arbitrator, a retired judge, sided with Kaiser’s doctors and experts, who questioned whether Fowler’s problems were caused by a deficiency of vitamin B12. — Melody Petersen, Los Angeles Times, 20 July 2026

Williams points out that beef supplies nutrients that many Americans don’t get enough of, including iron, zinc, and vitamin B12. — Lynn Andriani, Martha Stewart, 18 July 2026

This week’s wellness tips cover the best summer fruit for blood sugar, the strength training sweet spot for longevity, early signs of vitamin B12 deficiency, and simple ways to lower your blood pressure through exercise and diet. — Abby Norman, Verywell Health, 13 July 2026

Some of the largest increases in intake were seen in vitamin D, zinc, magnesium, vitamin B12 and turmeric. — Angelica Stabile, FOXNews.com, 30 June 2026

Eating squid and octopus can also help boost your levels of vitamin A and vitamin B12. — Mark Gurarie, Health, 25 June 2026

Word History

First Known Use

1948, in the meaning defined at sense 1

Kids Definition

vitamin B₁₂

noun

-ˈbē-ˈtwelv

: a member of the vitamin B complex that contains cobalt, occurs especially in liver, and is needed for normal blood formation, nerve function, and growth

also : any of several other compounds with similar activity

Medical Definition

vitamin B₁₂

noun

-ˈbē-ˈtwelv 

1

: a complex cobalt-containing compound C₆₃H₈₈CoN₁₄O₁₄P found in animal products (as meat and eggs) that is essential to normal blood formation, neural function, and growth and is used especially in treating pernicious and related anemias and in animal feed as a growth factor

called also cyanocobalamin

2

: any of several compounds similar to vitamin B₁₂ in action but having different chemistry