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
Some nutritional deficiencies are common in people with celiac disease, such as iron, vitamin B12, vitamin D, zinc, folate, and calcium.
—
Merve Ceylan, Health, 27 Aug. 2025
Goldsmith also said that vitamin B12—commonly added to plant milks, cereals and nutritional yeast—requires close attention.
—Daniella Gray, MSNBC Newsweek, 27 Aug. 2025
Therefore, people with diets low in these foods may be at risk for a vitamin B12 deficiency.
—Pamela Assid, Verywell Health, 25 Aug. 2025
For those who want to streamline their wellness routine, Bloom’s super powder pairs colostrum with vitamin B12, probiotics, and bovine collagen (type I and III) for an incredible morning boost.
—Brianna Peters, Vogue, 15 Aug. 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
Adding easily available ingredients, such as vitamin B12, wouldn’t make compounded versions of weight-loss drugs legal now that the shortage is over, according to GoodRx.
—Meg Wingerter, Denver Post, 15 July 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.
Merve Ceylan, Health, 27 Aug. 2025
Goldsmith also said that vitamin B12—commonly added to plant milks, cereals and nutritional yeast—requires close attention.
—Daniella Gray, MSNBC Newsweek, 27 Aug. 2025
Therefore, people with diets low in these foods may be at risk for a vitamin B12 deficiency.
—Pamela Assid, Verywell Health, 25 Aug. 2025
For those who want to streamline their wellness routine, Bloom’s super powder pairs colostrum with vitamin B12, probiotics, and bovine collagen (type I and III) for an incredible morning boost.
—Brianna Peters, Vogue, 15 Aug. 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
Adding easily available ingredients, such as vitamin B12, wouldn’t make compounded versions of weight-loss drugs legal now that the shortage is over, according to GoodRx.
—Meg Wingerter, Denver Post, 15 July 2025
Cite this Entry
“Vitamin B12.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/vitamin%20B12. Accessed 9 Sep. 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