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

Some experts also warn about the potential for nutrient deficiencies — particularly vitamin B12, calcium and omega-3 fatty acids. —Kelly McGreal, FOXNews.com, 17 Nov. 2025

But other common wellness ingredients—such as coenzyme Q10, vitamin B12, folic acid, and zinc—require extra processing to permeate the body’s exterior, Glenn told me. —Yasmin Tayag, The Atlantic, 11 Nov. 2025

Infused with vitamin B12 to hydrate, nourish, and protect. —Emily Tannenbaum, Glamour, 10 Nov. 2025

Age and stress are often blamed for memory loss, but nutrient deficiencies (especially vitamin B12) play a significant role. —Brigid Dwyer, Verywell Health, 6 Nov. 2025

Infused with vitamin B12, vitamin C, magnesium and amino acids, this preservative-free formula is gentle on sensitive eyes and helps keep them comfortable and protected. —Adam Mills, MSNBC Newsweek, 8 Oct. 2025

The body needs vitamin B12 for neurological function, red blood cell production, DNA synthesis, and metabolism. —Jillian Kubala, Health, 7 Oct. 2025

B vitamins have been reported to help prevent Alzheimer’s disease and depression associated with vitamin B12 deficiency. —Alessandra Signorelli, Vogue, 12 Sep. 2025

Older adults are more likely to develop vitamin B12 deficiencies because the vitamin requires stomach acid to be absorbed, and stomach acid production starts to decline with age. —Perri Ormont Blumberg, Time, 13 Aug. 2025

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