Which vitamin is often linked to energy metabolism and is essential for cellular function?

Which vitamin is often linked to energy metabolism and is essential for cellular function?

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

Answer: (A)

Energy production in cells relies on carrier molecules that shuttle electrons during metabolism. Niacin provides the essential coenzymes NAD+ and NADP+. NAD+ accepts electrons during glycolysis and the citric acid cycle, becoming NADH, which then donates electrons to the electron transport chain to drive ATP synthesis. NADP+ is used in anabolic reactions and in maintaining redox balance with NADPH. Because these coenzymes are required across many steps that convert nutrients into usable energy and cellular building blocks, niacin is closely tied to energy metabolism and overall cellular function. The other vitamins listed have important roles—such as collagen formation and antioxidant protection for vitamin C, lipid-soluble antioxidant roles for vitamin E, and blood clotting for vitamin K—but they are not primarily linked to energy metabolism.

Energy production in cells relies on carrier molecules that shuttle electrons during metabolism. Niacin provides the essential coenzymes NAD+ and NADP+. NAD+ accepts electrons during glycolysis and the citric acid cycle, becoming NADH, which then donates electrons to the electron transport chain to drive ATP synthesis. NADP+ is used in anabolic reactions and in maintaining redox balance with NADPH. Because these coenzymes are required across many steps that convert nutrients into usable energy and cellular building blocks, niacin is closely tied to energy metabolism and overall cellular function. The other vitamins listed have important roles—such as collagen formation and antioxidant protection for vitamin C, lipid-soluble antioxidant roles for vitamin E, and blood clotting for vitamin K—but they are not primarily linked to energy metabolism.