Which pair of B vitamins is produced by the gut bacteria and is important for energy metabolism?

• A. Pantothenic acid and Biotin
• B. Niacin and Riboflavin
• C. Thiamine and Folate
• D. Vitamin A and D

Answer: (A)

The nutrients in question are two B vitamins that gut bacteria can synthesize, and both play essential roles in energy metabolism. Pantothenic acid, or vitamin B5, is a building block of coenzyme A. CoA carries and transforms acyl groups in many metabolic reactions, so it’s central to producing and using energy from carbohydrates, fats, and proteins, especially through the formation of acetyl-CoA that feeds the citric acid cycle and supports fatty acid metabolism. Biotin, or vitamin B7, acts as a coenzyme for several carboxylase enzymes—pyruvate carboxylase (important for gluconeogenesis), acetyl-CoA carboxylase (fatty acid synthesis), and propionyl-CoA carboxylase (metabolism of certain amino acids and odd-chain fatty acids). When gut bacteria supply these vitamins, they support the body’s energy-producing pathways.

Other listed vitamins also contribute to energy metabolism, but the pair uniquely highlighted for gut bacterial synthesis and this metabolic role are pantothenic acid and biotin. Vitamins A and D are not B vitamins and are not the focus here.