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

Conflicting test results indicating a potential allergy danger caused the manufacturer of vitamin B12 gummies to recall them nationwide. —David J. Neal, Miami Herald, 15 June 2025

The research found evidence that vitamin B12 status plays an important role in how responsive someone is to the effects of garlic on blood pressure.6 5. —Kathi Valeii, Verywell Health, 9 June 2025

Changes in nail texture may reflect nutritional deficiencies—including low levels of iron, biotin, zinc, magnesium, or vitamin B12—or systemic illnesses such as thyroid disorders, autoimmune diseases, or liver and kidney dysfunction. —Lydia Patrick, MSNBC Newsweek, 22 May 2025

Nitrous oxide inactivates vitamin B12 in the body, a crucial nutrient for the formation of red blood cells and the proper functioning of the nervous system. —Ella Jeffries, Smithsonian Magazine, 8 Apr. 2025

The body needs vitamin B12 for neurological function, red blood cell production, DNA synthesis, and metabolism. —Jillian Kubala, Health, 1 Apr. 2025

These doses seem significantly higher than the RDA of vitamin B12, but your body absorbs only a small percentage of them.1 Other Considerations Vitamin B12 is generally safe. —Emmanuella Ogbonna, Health, 29 Apr. 2025

In particular, not getting enough of three essential nutrients – vitamin D, vitamin B12 and omega-3 fatty acids – is linked to low energy levels. —Lina Begdache, The Conversation, 7 Jan. 2025

Oral vitamin B12 supplements are usually sufficient to maintain daily requirements. —Emmanuella Ogbonna, Health, 29 Apr. 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