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
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
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
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
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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
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
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 30 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
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