Vitamin K
Vitamin K is found in leafy green vegetables and cereal grains. For every kilogram of their body weight adults must consume 0.001mg of Vitamin K. Vitamin K is a very important fat-soluble molecule that has several functions in humans and is required for blood clotting due to it's role in synthesising specific proteins which are required for coagulation. The calcification of arteries and other soft tissues may be a result of low vitamin k levels - this can also cause weakened bones.