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

She warns that if you don't regularly consume these types of foods, you're probably also short of other essential nutrients like vitamin C, vitamin K, fibre and prebiotics too.

From BBC • Oct. 24, 2025

Delving deeper, the researchers conducted structural simulations and molecular docking studies to elucidate whether the vitamin K homolog interacts with mGluR1.

From Science Daily • Oct. 14, 2025

For example, leafy greens with high amounts of vitamin K can lower the effectiveness of the blood thinner warfarin.

From Salon • Sep. 18, 2023

Women should also include food sources of calcium, vitamin K and magnesium.

From Seattle Times • May 8, 2023

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