What is the role of vitamin C in collagen synthesis and iron absorption?

• A. Vitamin C inhibits iron absorption
• B. Vitamin C is a structural protein in collagen
• C. Vitamin C is a cofactor for collagen synthesis and enhances absorption of nonheme iron
• D. Vitamin C only prevents colds

Answer: (C)

Vitamin C supports two important functions in nutrition: helping collagen form properly and boosting the absorption of nonheme iron.

In collagen synthesis, vitamin C acts as a reducing cofactor for the enzymes prolyl hydroxylase and lysyl hydroxylase. These enzymes add hydroxyl groups to specific proline and lysine residues on the procollagen molecule. That hydroxylation is essential for stabilizing the collagen triple helix, which in turn gives connective tissue its strength. Without enough ascorbate, these hydroxylations falter, collagen becomes defective, and wound healing declines.

For iron absorption, vitamin C promotes the uptake of nonheme iron by reducing ferric iron (Fe3+) to the more soluble ferrous form (Fe2+). This keeps iron in a state that is easier to absorb in the intestinal lining and can form a complex that enhances transport into enterocytes. This effect is particularly relevant for nonheme iron found in plant-based foods, while heme iron from animal sources is less affected by vitamin C.

So, vitamin C is not a structural component of collagen, nor does it inhibit iron absorption or merely prevent colds. It serves as a crucial helper in both collagen formation and efficient nonheme iron absorption.