Which vitamin is essential for amino acid metabolism and glycogen breakdown, supporting immune and nervous system health?

• A. Vitamin B12
• B. Vitamin D
• C. Vitamin B6
• D. Vitamin C

Answer: (C)

Vitamin B6 works as a coenzyme in many reactions that handle amino acids, enabling transamination, decarboxylation, and deamination. This lets the body metabolize amino acids into other compounds, synthesize important molecules, and support overall protein metabolism. It also acts as a cofactor for glycogen phosphorylase, the enzyme that helps break down glycogen to release glucose when needed. Beyond metabolism, B6 supports immune function and nervous system health by aiding the production of neurotransmitters and supporting immune cell activity. Other vitamins listed have important roles—B12 in red blood cell formation and nerve function, D in bone health and various body systems, C in collagen synthesis and antioxidant protection—but they don’t address amino acid metabolism and glycogen breakdown as directly as B6.