Vitamin K Research Paper

VITAMIN K AND BLOOD CLOTTING

Vitamin K is a naturally occurring vitamin, a fat-soluble vitamin. It is recognized for its role in the process of formation of blood clotting ("K" is derived from the German word "koagulation"), it is essential for the functioning of many proteins that are involved in many physiological processes (Brody T, 1999). There are two forms of naturally occurring vitamin K that are known as vitamin K1 and vitamin K2 (Figure 1). Vitamin K1 or other name is phylloquinone is synthesized by plants and it is the predominant form in the diet. Vitamin K2 or other name is menaquinones includes a range of vitamin K forms. Most menaquinones are synthesized by the human intestinal microbiota and it is present in animal products

The vitamin K cycle allows a little amount of vitamin K to be reused for many times in protein carboxylation, thus decrease the dietary requirement. Actually vitamin K in its reduced form known as hydroquinone is oxidized to oxidized form called as vitamin K epoxide. This reaction cause the amino acid (γ-glutamylcarboxylase) to carboxylate selective glutamic acid residues that is present on vitamin K-dependent proteins. The recycling of vitamin K is carried out by two reactions that reduce vitamin K epoxide (KO) to vitamin K and then vitamin K into vitamin K hydroquinone (KH2; Figure 2). Then, the enzyme vitamin K oxidoreductase catalyzes the reduction of vitamin K epoxide to vitamin K quinone and reductases cause the production of vitamin K hydroquinone from vitamin K quinone (Rishavy MA, 2013; Tie JK, 2011). The warfarin which is an anticoagulant drug functions as vitamin K antagonist by inhibiting vitamin K oxidoreductase activity, hence prevent from vitamin K