This test measures the amount of vitamin K in blood. Vitamin K is a group of fat-soluble vitamins essential for the functioning of several proteins involved in blood clotting. Insufficient vitamin K can lead to excessive bleeding and easy bruising. Vitamin K is also involved in maintaining healthy bones by assisting in the transportation of calcium from the blood to the bone. Without sufficient amounts of vitamin K, calcium can build up on the arterial wall resulting in vascular and cardiovascular problems. Vitamin K is also thought to play an important role in the prevention of bone loss. Low blood levels of vitamin K have been associated with low bone density, and maintaining adequate levels of vitamin K can improve bone health while reducing the risk of fractures. Sources-Vitamin K is found in green leafy vegetables and oils, such as olive, cotton seed, and soya bean. Other foods rich in vitamin K are green peas and beans, spinach, oats and whole wheat. Vitamin K is also synthesised by colonic bacteria