Which vitamin is known for its role in blood coagulation?

Vitamin K is known for its crucial role in blood coagulation, which is the process that prevents excessive bleeding when injuries occur. This vitamin is essential for the synthesis of certain proteins called clotting factors, which are necessary for proper clot formation. Without adequate vitamin K, the body cannot produce these proteins effectively, leading to increased bleeding risks and potential difficulties in wound healing.

Vitamin K exists in two main forms—K1 (phylloquinone), primarily found in leafy green vegetables, and K2 (menaquinone), which is found in fermented foods and some animal products. The action of vitamin K involves the carboxylation of specific glutamic acid residues on clotting factors, allowing them to bind calcium ions. This binding is critical for the subsequent interactions that lead to the formation of a stable blood clot.

In contrast, the other vitamins mentioned do not have a significant role in blood coagulation. For example, vitamin A is primarily involved in vision and immune function, vitamin D is important for calcium metabolism and bone health, and vitamin E serves as an antioxidant.