Foods rich in vitamin K include spinach, mustard greens, kale, Brussels sprouts, parsley and beet greens. Kale has one of the highest percentages of vitamin K, while Brussels sprouts are much lower in the nutrient. Vitamin K is often found in green, leafy vegetables.
Vitamin K is essential for aiding the body in the process of blood clotting. There are three essential types of vitamin K: K1, K2 and K3. K1 is found mostly in plant foods as it's required for the process of photosynthesis. K2 is a combination of K1 and K3 produced by interactions with micro-organisms and bacteria. K2 has also been known to be created naturally in the human body through a special conversion that takes place between K1 and K3. Unless the plant has been altered by micro-organisms, bacteria or fermentation, K2 isn't common in plant foods.
Of the 12 proteins required for the blood clotting process, four need vitamin K in order to become active. A vitamin K deficiency is more common in newborns because the vitamin can't properly travel from the placenta to the fetus. The deficiency is less common in healthy adults, appearing primarily in individuals who have a gastrointestinal or liver disease.