Vitamin K dependent factor true statement?

• A. They include factors II, VII, IX, and X
• B. They include factor VIII
• C. They are produced independently of liver function
• D. They are unaffected by anticoagulants

Answer: (A)

The key idea is which clotting factors require vitamin K for their production. The factors that depend on vitamin K are II, VII, IX, and X. They need a gamma-carboxylation step to become active, a modification that occurs in the liver using vitamin K. Because of this, the statement that these factors include II, VII, IX, and X is true.

Factor VIII, on the other hand, is not vitamin K–dependent; it’s produced mainly by endothelial cells and functions in the intrinsic pathway without requiring this vitamin-K–driven carboxylation.

These vitamin K–dependent factors are produced by the liver, so liver function is essential for their production; impaired liver function lowers their levels.

Anticoagulants, such as warfarin, inhibit the vitamin K cycle and reduce the synthesis of these factors (and also proteins C and S). So they are affected by anticoagulants, not unaffected.

That’s why the correct statement is that the vitamin K–dependent factors include II, VII, IX, and X.