Answer: D - Anticoagulants are vitamin K antagonists. Vitamin K is involved in the regulation of blood clotting. Because they prevent blood clotting, anticoagulants oppose the action of vitamin K. This isn't a bad thing. Rather it's the action of the anti-coagulant drugs. For example, the metabolism of warfarin (Coumadin), vitamin K, and vitamin K dependent clotting factors occurs in liver. Warfarin (Coumadin) prevents the production of vitamin K-dependent clotting factors. As a result, clotting occurs at a much slower rate.
Source: National Blood Clot Alliance
