vitamin K

British  

noun

1. any of the fat-soluble vitamins, including phylloquinone and the menaquinones, which are essential for the normal clotting of blood

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vitamin K Scientific  

1. Any of a group of fat-soluble vitamins that are involved in the formation of prothrombin and other clotting factors in the liver and are essential for normal clotting of the blood. (The K is derived from the German word koagulation.) Vitamin K is also involved in bone formation and repair. Two forms occur naturally: vitamin K ₁, which is synthesized by plants, and vitamin K ₂, which is mainly synthesized by intestinal bacteria. The other forms are synthetic substances with similar chemical structures.

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Example Sentences

See Examples For:

vitamin K

When the team tested the compounds in mouse neural progenitor cells, the hybrid molecules preserved the biological activity of both vitamin K and retinoic acid.

From Science Daily ● May 27, 2026

No vitamin K derived drug has yet been shown to repair the brains of people with Alzheimer's, Parkinson's, or Huntington's disease.

From Science Daily ● May 27, 2026

In work published online in ACS Chemical Neuroscience on July 03, 2025, researchers from Shibaura Institute of Technology in Japan created vitamin K analogues designed to be more active in the nervous system.

From Science Daily ● May 27, 2026

Two weeks ago, at a House subcommittee hearing, Rep. Kim Schrier, D-Wash., pressed Health and Human Services Secretary Robert F. Kennedy Jr. to reassure parents that the vitamin K shot is safe.

From Salon ● May 7, 2026

After suctioning the mucus from my nostrils, she gave me a shot of vitamin K to coagulate my blood.

From "Middlesex: A Novel" by Jeffrey Eugenides