vitamin K

British

noun

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

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

vitamin K Scientific

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.

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

To explore whether the vitamin K compound could interact with mGluR1, the researchers used structural simulations and molecular docking studies.

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

The team then investigated how vitamin K might be producing these neuroprotective effects.

From Science Daily • May 27, 2026

Determining precisely how many babies have died or suffered severe brain damage because of a lack of vitamin K is difficult.

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

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023