This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
[{'content': 'Which of the following deficiency in alcoholics inhibit pyruvate dehydrogenase? \nSelect and explain. \nA. Thiamin, B. Niacin, C. Riboflavin, D. Ascorbic acid', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Arsenite and mercuric ions react with the - SH groups of lipoic acid and inhibit pyruvate dehydrogenase, as does a dietary deficiency of thiamin, allowing pyruvate to accumulate. Many alcoholics are thiamin-deficient (both because of a poor diet and also because alcohol inhibits thiamin absorption), and may develop potentially fatal pyruvic and lactic acidosis. Ref: Harper 28th edition, Chapter 17.', 'role': 'assistant'}]