also known as phylloquinone, is present mostly in dark, leafy green vegetables .helps with supporting normal, healthy blood clotting and bone structure. Vitamin K is also a key factor in protein synthesis within the body. The form of Vitamin K-1 in this supplement can be converted in the body to Vitamin K2 MK-4 when Vitamin K2 is needed. Also known as phylloquinone, is present mostly in dark, leafy green vegetables .helps with supporting normal, healthy blood clotting and bone structure.Vitamin K is also a key factor in protein synthesis within the body. The form of Vitamin K-1 in this supplement can be converted in the body to Vitamin K2 MK-4 when Vitamin K2 is needed.