VITAMIN K

Vitamin K is a fat-soluble vitamin. This vitamin is very important for blood clotting and bone strength. Naturally, it has two main parts: vitamin K1 and vitamin K2. Vitamin K1 is abundant in vegetables especially green leafy vegetables while vitamin K2 is present in animal foods while it is also synthesized by bacteria in colon including conversion of vitamin K1to K2. 

Functions of Vitamin K

Vitamin K1 or Phylloquinone is very important for blood-clotting because of its main function in the production of coagulation factors II, VII, IX & X in liver. In its deficiency or absence, lot of blood can be lost from body after an injury due to weakness or failure of blood-clotting function.

Vitamin K2 or menaquinones is very important for bone density and strength. Its deficiency can cause different bones to be easily fractured due to fragility. 

Presence in Foods

Different green leafy vegetables including kale, spinach, turnip, cabbage etc. are rich in vitamin K1. The presence of this vitamin increases many folds when these vegetables are cooked.

Vitamin K2 is abundant in animal foods especially egg yolk, butter, chicken liver, cheddar cheese, chicken meat etc. 

Bacteria in colon can also synthesize vitamin K2 from vitamin K1. Using antibiotics in large amounts can destroy colon bacteria that can cause vitamin K2 deficiency.

RDI & UL

Recommended Daily Intake of Vitamin K is 120 micrograms/day for adult male and 90 micrograms/day for adult female.

There is no toxicity proved for naturally acquired vitamin K1 and K2. Therefore, there is no upper tolerable limit for vitamin K taken through diet.