Wernicke-Korsakoff syndrome results from deficiency of which vitamin?

• A. Vitamin B1
• B. Vitamin B12
• C. Vitamin B6
• D. Vitamin B9

Answer: (A)

Thiamine deficiency (vitamin B1) is what drives Wernicke-Korsakoff syndrome. Thiamine is a crucial cofactor for enzymes in glucose metabolism, so when levels are low the brain’s energy production falters, especially in areas with high metabolic demands like the mammillary bodies and thalamus. That energy shortfall leads to the acute Wernicke encephalopathy symptoms—eye movement abnormalities, unsteady gait, and confusion—and, if not treated promptly, evolves into Korsakoff syndrome, characterized by severe memory impairment with confabulation. It’s most common in chronic alcohol use due to poor intake, malabsorption, and depleted stores. Treatment requires rapid, high-dose thiamine, typically given intravenously before glucose, followed by ongoing supplementation and efforts to address alcohol use and nutrition.