Which vitamin functions as an antioxidant and is linked to reduced risk of heart disease and cancer?

• A. Vitamin A
• B. Vitamin K
• C. Vitamin B12
• D. Vitamin E

Answer: (D)

Vitamin E is the one that acts as an antioxidant. It’s a fat-soluble vitamin that protects cell membranes from oxidative damage by neutralizing free radicals, especially protecting fatty components of cells from lipid peroxidation. This antioxidant role is why it’s linked in many sources to a lower risk of heart disease and cancer, though evidence from supplements is not conclusive. Foods rich in vitamin E include vegetable oils, nuts, seeds, and green leafy vegetables. The other vitamins have different primary roles—Vitamin A supports vision and immunity; Vitamin K is essential for blood clotting; Vitamin B12 is needed for red blood cell formation and nervous system function—so they don’t fit the description of an antioxidant linked to reduced disease risk.