Which vitamin is associated with wound healing and blood clotting?

• A. Vitamin A
• B. Vitamin E
• C. Vitamin D
• D. Vitamin K

Answer: (D)

Vitamin K is essential for blood clotting, which is the first critical step in wound healing. It activates several clotting proteins—like prothrombin and factors II, VII, IX, and X—through a process called gamma-carboxylation. This modification lets these proteins bind calcium and assemble properly on cell surfaces to form a stable clot that stops bleeding. Without enough vitamin K, the clotting factors can’t function well, leading to excessive bleeding and delays in healing. Other vitamins support health in different ways—A helps with skin and immune function, E is an antioxidant, and D supports bone health—but they don’t play the key role in coagulation that vitamin K does.