The hemorrhagic problems associated with scurvy are due to a deficiency of what cofactor required for collagen synthesis?

• A. Vitamin C
• B. Prothrombin
• C. Vitamin K
• D. Protein C

Answer: (A)

The issue in scurvy hemorrhages is impaired collagen maturation caused by lack of vitamin C. Ascorbic acid acts as a reducing cofactor for the enzymes that hydroxylate specific amino acids—proline and lysine—in procollagen. This hydroxylation is necessary for the collagen triple helix to form correctly and for collagen to be stable and secreted into the extracellular matrix. When this step is defective, collagen fibers are weak, making blood vessel walls fragile and prone to hemorrhage, which explains the easy bruising, gum bleeding, and poor wound healing seen in scurvy. The other options involve components of the coagulation system; deficiencies here cause bleeding from insufficient clot formation rather than the collagen synthesis defect characteristic of scurvy. Therefore, vitamin C is the essential cofactor missing.