Riboflavin, thiamin, and niacin are all involved in the metabolism of which nutrient?

The correct answer is that riboflavin, thiamin, and niacin are all involved in the metabolism of carbohydrates. These B vitamins play key roles in the enzymatic processes that convert carbohydrates into energy.

Thiamin (Vitamin B1) is essential for the decarboxylation of pyruvate to acetyl-CoA, a crucial step in carbohydrate metabolism where glucose is broken down to provide energy. Riboflavin (Vitamin B2) is part of the coenzymes FAD and FMN, which are involved in energy production pathways, including the Krebs cycle and fatty acid oxidation, supporting the overall metabolism of macronutrients, including carbohydrates. Niacin (Vitamin B3) is primarily involved in the formation of NAD and NADP, which are vital coenzymes in various metabolic reactions, facilitating the conversion of carbohydrates into energy.

The involvement of these vitamins highlights their critical functions in ensuring proper energy metabolism from carbohydrate sources, underscoring why the option related to carbohydrates is the correct choice.