Question

Which of the following are needed for blood clotting?

• A. Ca${}^{++}$ and vitamin E
• B. Ca${}^{++}$ and vitamin K
• C. K${}^{+}$ and vitamin A
• D. K${}^{+}$ and vitamin K

Answer 1

Answer: (B)

Ca${}^{++}$ and vitamin K

Calcium ion and vitamin K are needed for blood clotting. Coagulation (thrombogenesis) is the process by which blood forms clots.
Vitamin K adds a carboxyl group to multiple factors of the coagulation cascade. In adding the gamma-carboxyl group to glutamate residues on the immature clotting factors, Vitamin K is itself oxidized.

Calcium mediates the binding of the complexes to the phospholipid surfaces expressed by platelets.

Hence, correct answer is option B.