Which vitamin is essential for blood clotting?

Vitamin K is essential for blood clotting due to its critical role in the synthesis of certain proteins known as clotting factors. These proteins are necessary for the blood coagulation process, which helps stop bleeding. Without sufficient vitamin K, the body cannot produce these clotting proteins, leading to an increased risk of excessive bleeding even from minor injuries. This vitamin is unique because it is involved in post-translational modifications of proteins, specifically the carboxylation of certain glutamate residues, which allows the proteins to bind calcium ions necessary for their activity in the coagulation cascade.

In contrast, while vitamins A, D, and C play vital roles in various bodily functions—such as vision, bone health, and immune function, respectively—they are not directly involved in the blood clotting process. Understanding the specific functions of each vitamin helps clarify their importance in nutrition and health.