Which vitamin is essential for a patient on Coumadin to prevent serious injury?

A. Vitamin D is important for bone health but does not directly affect Coumadin (warfarin) therapy. B. Vitamin K plays a critical role in blood clotting. Coumadin works by inhibiting vitamin K–dependent clotting factors, so maintaining a consistent intake of vitamin K is essential to prevent fluctuations in anticoagulation and reduce the risk of bleeding or clotting complications. C. Vitamin C is important for immune function and tissue repair but does not directly interact with Coumadin. D. Vitamin B12 is necessary for red blood cell production and nervous system function but is not directly related to Coumadin therapy or prevention of bleeding complications.