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

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

Novel VK also converted into MK-4 more easily than natural vitamin K.

From Science Daily • May 27, 2026

To make vitamin K more potent, the team synthesized 12 hybrid vitamin K homologs.

From Science Daily • May 27, 2026

Still, six medical specialists and one official at the CDC said a meaningful portion of those deaths likely were caused by vitamin K deficiency.

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