Vitamin K is a fat-soluble vitamin that is seen widely in green leafy vegetables. Our body needs Vit-K to produce a type of protein called prothrombin that is required for blood clotting.
There are two main kinds of vitamin K. Vitamin K1 (phylloquinone) comes from plants – especially leafy green vegetables, while Vitamin K2 (menaquinone) come from meat (in small quantities). Vit K2 is also naturally created in our intestinal tract from Vit-K1 and is stored in the liver for future use.
Apart from helping the blood to clot, Vit K is also required for making a protein named osteocalcin, seen in bone. The deficiency of Vit-k can cause brittle bones and can also cause internal bleeding.
While 90 – 100 microgram is the prescribed daily intake level of Vit-K for an adult, there is no particular upper limit set, as the toxicity due to Vit-K is very low and is highly unlikely to cause by eating Vit-k rich food.
However, Vit-K can counteract with anticoagulant/antiplatelet (blood thinner) medications such as Warfarin. Anticoagulants are used to prevent blood from clotting and if Vit-k intake is higher, it may induce clotting tendency.
Vitamin K supplementation should be taken ONLY after the recommendation of a doctor, especially if you are on any medications such as anticoagulants, cholesterol-lowering drugs, anti-epileptic drugs etc.