Which vitamin deficiency is known to cause increased clotting time in blood?

Vitamin K plays a crucial role in the process of blood coagulation, helping to synthesize proteins that are essential for blood clotting, such as prothrombin and several clotting factors. When there is a deficiency in vitamin K, the body struggles to produce these necessary proteins, leading to a prolonged clotting time. This condition can result in increased risk of bleeding, as the body is impaired in its ability to form clots effectively.

In contrast, while other vitamins such as B12 can affect blood health by influencing red blood cell production and overall blood quality, they do not directly influence the coagulation process in the same critical manner as vitamin K does. Similarly, vitamins A and D have important functions in the body but are not directly linked to blood clotting mechanisms. Understanding these functions clarifies why vitamin K deficiency specifically results in increased clotting time.