vitamin B12
noun
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
Combining creatine with nutrients like vitamin B12 may also help promote better overall energy and heart function.
—
Angelica Stabile, FOXNews.com, 11 Oct. 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
It’s also infused with collagen and pink vitamin B12 to soften fine lines, restore elasticity, and refine skin texture.
—Christa Joanna Lee, Allure, 4 Oct. 2025
The best sources of vitamin B12 are found in foods such as milk, eggs, poultry, and seafood.
—Alexa Mikhail, Flow Space, 1 Oct. 2025
Research provides no specific vitamin B12 and magnesium dosage to boost energy levels.
—Amy Brownstein, Verywell Health, 16 Sep. 2025
Bivalve molluscs such as mussels and clams, as well as tellinas and oysters, contain significant amounts of vitamin B12 and riboflavin, as well as thiamine, niacin, and folic acid.
—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
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.
Angelica Stabile, FOXNews.com, 11 Oct. 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
It’s also infused with collagen and pink vitamin B12 to soften fine lines, restore elasticity, and refine skin texture.
—Christa Joanna Lee, Allure, 4 Oct. 2025
The best sources of vitamin B12 are found in foods such as milk, eggs, poultry, and seafood.
—Alexa Mikhail, Flow Space, 1 Oct. 2025
Research provides no specific vitamin B12 and magnesium dosage to boost energy levels.
—Amy Brownstein, Verywell Health, 16 Sep. 2025
Bivalve molluscs such as mussels and clams, as well as tellinas and oysters, contain significant amounts of vitamin B12 and riboflavin, as well as thiamine, niacin, and folic acid.
—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
Cite this Entry
“Vitamin B12.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/vitamin%20B12. Accessed 21 Oct. 2025.
Copy CitationMedical Definition
vitamin B12
noun1
: 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
Love words? Need even more definitions?
Merriam-Webster unabridged
Share