Anatomy and Physiology II Practice Test

Which type of vitamin is essential for the synthesis of blood clotting factors?

1. Vitamin A

2. Vitamin K

3. Vitamin D

4. Vitamin B

The correct answer is: Vitamin K

Vitamin K plays a crucial role in the synthesis of blood clotting factors, which are essential for the coagulation process. Specifically, vitamin K is involved in the post-translational modification of certain proteins, allowing them to bind calcium ions, which is necessary for their activity in the clotting cascade. Without sufficient levels of vitamin K, the body cannot produce these clotting factors effectively, leading to impaired blood coagulation and an increased risk of bleeding. The significance of vitamin K is particularly evident in the function of factors II (prothrombin), VII, IX, and X—key proteins in the coagulation pathway that depend on this vitamin for their synthesis in the liver. This highlights the essential nature of vitamin K in maintaining hemostasis and preventing excessive bleeding.