Wernicke encephalopathy results from deficiency of which vitamin?

• A. Thiamine (Vitamin B1)
• B. Riboflavin (Vitamin B2)
• C. Niacin (Vitamin B3)
• D. Ascorbic Acid (Vitamin C)

Answer: (A)

Thiamine deficiency leads to Wernicke encephalopathy because thiamine (Vitamin B1) is essential for brain energy production. It acts as a cofactor for enzymes in carbohydrate metabolism, such as pyruvate dehydrogenase and α-ketoglutarate dehydrogenase. Without enough thiamine, brain cells can’t generate the ATP they need, causing the neurologic symptoms seen in Wernicke—eye movement abnormalities, gait instability, and confusion. This condition is a medical emergency and requires prompt thiamine replacement; in practice, thiamine is given before glucose to prevent worsening neurologic damage. Other vitamins listed are linked to different deficiency syndromes (riboflavin with mucous membrane changes, niacin with pellagra, vitamin C with scurvy), not Wernicke encephalopathy.