This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Vitamins and Minerals, Subject name: Biochemistry
[{'content': 'Which of the following vitamin deficiency causes pellagra? \nSelect and explain. \nA. Thiamine, B. Ascorbic acid, C. Nicotinic acid, D. Cyanocobalamine', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. c (Nicotinic acid). (Ref. Harrison, Medicine, 14th ed., 463)NIACIN# Function: CoA enzyme in redox reactions.# 1 mg of niacin is formed from 60 mg of tryptophan.# Deficiency: Pellagra (diarrhea, dermatitis, dementia and death if untreated).# Hartnup disease, malignant carcinoid syndrome and INH therapy may also cause niacin deficiency.', 'role': 'assistant'}]