Vitamin K assay measures the concentration of vitamin K in the blood. Vitamin K is a fat-soluble vitamin, available as vitamin K1 (phylloquinone) and vitamin K2 (menaquinone), involved in blood clotting and bone metabolism. This test indicates easy bruising, impaired clotting, and increased bleeding tendencies secondary to vitamin K deficiency due to poor absorption, metabolism or utilization. The test provides personalized recommendations.