Vitamin K deficiency is a form of avitaminosis resulting from insufficient vitamin K1 or vitamin K2 or both.
Vitamin K1 Deficiency
Vitamin K1-deficiency may occur by disturbed intestinal uptake (such as would occur in a bile duct obstruction), by therapeutic or accidental intake of a vitamin K1-antagonist such as warfarin, or, very rarely, by nutritional vitamin K1 deficiency. As a result, Gla-residues are inadequately formed and the Gla-proteins are insufficiently active.