Canadian Society for Medical Laboratory Science (CSMLS) Practice Exam

Which vitamin is essential for blood coagulation?

1. Vitamin A

2. Vitamin C

3. Vitamin K

4. Vitamin E

The correct answer is: Vitamin K

Vitamin K is essential for blood coagulation because it plays a critical role in the synthesis of certain proteins known as clotting factors, which are necessary for the blood clotting process. These proteins help in the formation of fibrin, a key component that stabilizes blood clots and stops bleeding. When vitamin K is deficient, the body cannot produce adequate amounts of these clotting factors, leading to an increased risk of excessive bleeding and hemorrhagic disorders. This vitamin is primarily obtained through dietary sources such as green leafy vegetables, certain fruits, and fermented foods. Other vitamins, while important for various bodily functions, do not have a direct role in blood coagulation. For instance, vitamin A is crucial for vision and immune function, vitamin C is important for collagen synthesis and immune health, and vitamin E acts as an antioxidant. Therefore, none of these options support the coagulation process in the way that vitamin K does.