vitamin K n.
Any of several fat-soluble compounds that are found in alfalfa, hog liver, fish meal, and vegetable oils and are essential for the production of normal amounts of prothrombin. Also called antihemorrhagic factor.
| vitamin K
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 K1, which is synthesized by plants, and vitamin K2, which is mainly synthesized by intestinal bacteria. The other forms are synthetic substances with similar chemical structures. |