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
Wernicke encephalopathy is due to acute dietary deficiency of: 
Select and explain. 
A. Folic acid, B. Nicotinic acid, C. Thiamine, D. Pyridoxine
C: Thiamine
Answer: C: Thiamine 
Explanation: Wernicke's (ophthalmoparesis, ataxia, and encephalopathy) and Korsakoff's(retrograde and anterograde amnesia) syndrome is common in alcoholics due to thiamine deficiency. Pathogenesis:- Thiamine is needed for oxidative decarboxylation reactions (pyruvate dehydrogenase and a-ketoglutarate dehydrogenase) that are very impoant for the metabolism of glucose. Thiamine deficiency produces a diffuse decrease in cerebral glucose utilization and results in mitochondrial damage. Glutamate accumulates due to impairment of a-ketoglutarate dehydrogenase activity and, in combination with the energy deficiency,may result in excitotoxic cell damage.