How Vitamin-K helps in Coagulation (Clotting) ?

INTRODUCTION

      Vitamin-K is the only Fat-soluble vitamin with a specific co-enzyme function. As it is required for the production of clotting factors that's why (In german, Coagulation is called "koagulation") so that's why it's named as Vitamin-K.

TYPES OF VITAMIN-K

Different types of vitamin-k are their, three are given below:

1. Vitamin-K1: Also called Phylloquinone and its is present in Plants.

2. Vitamin-K2: Also called Menaquinone, normally synthesized by intestinal bacterias and present in Animals.

3. Vitamin-K3: Also called Menadione, and its a synthetic Vitamin.

METABOLISM

     Normally Vitamin-K is taken in the diet or synthesized by intestinal bacteria, and then absorbed along with fats in the intestine in the presence of bile salts. Its transported with LDL and stored in the liver.

HOW VITAMIN-K HELPS IN COAGULATION?

     Normally Vitamin-K play an important role in the Post-translational modification of certain clotting factors (Factor II, VII, IX, X). These factors have glutamic residues, that are carboxylated by the Vitamin-K in the presence of CO2 and O2. As a result Gamma-Carboxyglutamic Acid residue is obtained, that is the activated form of clotting factor. This reaction have a product called 2,3-epoxide, that is then converted to active Vitamin-K with the help of reductase enzyme.

     But before activation, the gamma-carboxyglutamic acid make complex with the positive calcium, that then binds with the phospholipids on the membrane surfaces of platelet. Then, it leads to the increase conversion of Prothrombin to Thrombin.

     There are some anti-coagulants that inhibit the reductase enzyme that leads to the inhibition of active Vitamin-K, these anti-coagulants include Dicumarol and Warfarin.

DEFICIENCY OF VIT-K

     Normally deficiency of Vitamin-K is uncommon, but it may occur due to the fault in Vitamin-K absorption, lack of bile salts, Administration of antibiotics that leads to the killing of intestinal flora.

     Deficiency of Vitamin-K leads to the lack of activated Prothrombin, which causes adverse blood coagulation. Then ultimately results in the prolongation of Blood clotting time.