Assistant Laboratory Animal Technician (ALAT) Practice Exam

Which vitamin is primarily responsible for blood clotting?

1. Vitamin C

2. Vitamin D

3. Vitamin K

4. Vitamin A

The correct answer is: Vitamin K

Vitamin K plays a vital role in the blood clotting process, which is essential for preventing excessive bleeding when injuries occur. It acts as a cofactor for the enzymes responsible for the synthesis of certain proteins that are critical for the coagulation cascade, including prothrombin, which is necessary for the formation of blood clots. Without adequate vitamin K, blood clotting is impaired, leading to conditions such as easy bruising and increased bleeding tendencies. In contrast, vitamin C is primarily known for its role in collagen synthesis and immune function rather than blood clotting. Vitamin D is critical for calcium absorption and bone health but does not play a direct role in the coagulation process. Vitamin A is essential for vision and immune function, as well as cellular communication, but it does not contribute to blood clotting.