Vitamin K, Osteoarthritis, and Athletic Performance

Abstract

Vitamin K is a fat-soluble vitamin that is required for modification of proteins needed for blood clotting. Vitamin K also is important for bone mineralization, cell growth, and metabolism of blood vessel walls. There are three forms of vitamin K: vitamin K1 or phylloquinone, vitamin K2 or menaquinone, and vitamin K3 or menadione (see Figure for chemical forms). Phylloquinone is of plant origin and used mainly for blood clotting. Menaquinone is produced typically by probiotic bacteria in the large intestine, although it also is found in small amounts in meat, fish, and fermented food. Menaquinone is important in bone mineralization, cell growth, and metabolism of blood vessel walls. Menadione is the synthetic form of vitamin K and not used in humans and also is known as a “menaphthone.” Although vitaminK is studiedmainly for its blood-clotting role and its role in bone mineral density, there has been research on vitaminK and osteoarthritis. In this ANutritionist’s View article, I will