Which vitamin is NOT a dietary antioxidant?

The correct choice is Vitamin K. While many vitamins have antioxidant properties, Vitamin K is primarily known for its essential role in blood clotting and bone health. It does not function as a dietary antioxidant in the way that the other options do.

Lycopene, beta-carotene, and vitamin E all act as antioxidants, helping to neutralize free radicals in the body. Lycopene, found in tomatoes and other red fruits, is recognized for its potential to reduce the risk of certain chronic diseases by acting as an antioxidant. Beta-carotene, which the body can convert into vitamin A, is another antioxidant that contributes to immune function and skin health. Vitamin E is a well-known antioxidant that helps protect cell membranes from oxidative damage.

In contrast, the primary biochemical functions of Vitamin K do not include acting as an antioxidant, which makes it the correct choice for this question.