vitamin B12

noun

-ˈbē-ˈtwelv How to pronounce vitamin B{inf}12{/inf} (audio)
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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Its vitamin B12 supports your nerves and blood cells. — Caroline Hopkins Legaspi, New York Times, 25 Nov. 2024 Less frequent side effects can include chest discomfort, weakness, headache, rhinitis, hypoglycemia and vitamin B12 deficiency (with long-term metformin use). — Leslie Baumann, Miami Herald, 27 Feb. 2025

Word History

First Known Use

1948, in the meaning defined at sense 1

Time Traveler
The first known use of vitamin B12 was in 1948

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“Vitamin B12.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/vitamin%20B12. Accessed 21 Mar. 2025.

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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 How to pronounce vitamin B{inf}12{/inf} (audio)
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

More from Merriam-Webster on vitamin B12

Britannica.com: Encyclopedia article about vitamin B12

Last Updated: - Updated example sentences
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