Which one of the following vitamins has a role in blood clotting ?

Vitamin K is fundamentally known as the "clotting vitamin" due to its indispensable role in the blood coagulation process. It serves as a vital co-factor for the enzyme gamma-glutamyl carboxylase, which facilitates the synthesis of several key coagulation proteins in the liver, specifically clotting factors II (prothrombin), VII, IX, and X. This biochemical process allows these factors to bind calcium ions, which is essential for the clotting cascade to function correctly and prevent excessive bleeding. While other vitamins have distinct roles—such as Vitamin A for vision, Vitamin B for metabolism, and Vitamin D for calcium absorption and bone health—only Vitamin K is directly responsible for the synthesis of hemostatic proteins. A deficiency in Vitamin K leads to impaired coagulation and increased susceptibility to bruising and hemorrhaging.

Sources

1. [1] https://medlineplus.gov/ency/article/002407.htm
2. [2] https://www.ncbi.nlm.nih.gov/books/NBK551578/
3. [3] https://www.sciencedirect.com/science/article/pii/S0002916522037686