This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: vitamins, Subject name: Biochemistry
Glutathione requires which vitamin to act as antioxidant 
Select and explain. 
A. Vitamin E, B. Niacin, C. Vitamin C, D. Vitamin A
B: Niacin
Answer: B: Niacin 
Explanation: Glutathione peroxidase: It detoxifies H2O2 to H2O, while reduced glutathione (G SH) is conveed to oxidized glutathione (GS SG). The reduced glutathione can be regenerated by the enzyme glutathione reductase utilizing NADPH The hexose monophosphate shunt is the major source of NADPH. ref Satyanarayana 4th ed page 659