Excess of which vitamin leads to decreased synthesis of vitamin K coagulation factors?

Excess vitamin E can interfere with the vitamin K-dependent coagulation factors by inhibiting the action of vitamin K. Vitamin K is essential for the synthesis of several clotting proteins including factors II (prothrombin), VII, IX, and X in the liver. These factors require vitamin K as a cofactor for their post-translational modification, which includes carboxylation of specific glutamic acid residues, a process critical for their activity.

High levels of vitamin E can act as an antioxidant, which may inhibit the vitamin K dependent carboxylation reaction. This results in a functional deficiency of vitamin K despite adequate levels of the vitamin itself, leading to decreased synthesis of coagulation factors and potentially increased bleeding risk.

Other vitamins such as A, C, and D do not have this specific inhibitory relationship with vitamin K and its role in clotting factor synthesis. Vitamin A is involved in vision and immune function; vitamin C is important for collagen synthesis and antioxidant protection; and vitamin D is crucial for calcium metabolism and bone health. None of these vitamins affect the synthesis of vitamin K-dependent clotting factors in the manner that excess vitamin E does.