B vitamins B1, B2, B3, and Bs are required for energy production from which nutrients?

• A. Carbohydrates, fats, and proteins
• B. Proteins only
• C. Carbohydrates only
• D. Fats only

Answer: (A)

B vitamins serve as essential coenzymes in energy metabolism, enabling the body to extract energy from all three major macronutrients: carbohydrates, fats, and proteins. They help drive the key steps where fuel is converted into usable energy inside cells. For example, thiamine (B1) is needed for the decarboxylation of glucose-derived pyruvate so it can enter the TCA cycle; riboflavin (B2) and niacin (B3) provide crucial redox carriers (FAD/FMN and NAD+/NADP+) for reactions in glycolysis, the TCA cycle, and the electron transport chain. Pantothenic acid (B5) forms CoA, which is essential for making acetyl-CoA from carbohydrates, fats, and some amino acids, feeding each pathway into energy production. Because these vitamins support multiple enzymes across these pathways, they are required for energy yield from carbohydrates, fats, and proteins, not just one nutrient. If any of these vitamins are deficient, energy production from all fuel sources can be compromised.