Which of the following deficiency in alcoholics inhibit pyruvate dehydrogenase?: (A) Thiamin, (B) Niacin, (C) Riboflavin, (D) Ascorbic acid
Answer is A. 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.