Which vitamin is primarily deficient due to alcoholism and is essential for neurological function?

The vitamin primarily deficient due to alcoholism that is essential for neurological function is thiamine (B1). Chronic alcohol consumption can lead to malnutrition and impaired absorption of nutrients, particularly thiamine. Thiamine deficiency is closely associated with classic neurological disorders in the context of alcoholism, such as Wernicke's encephalopathy and Korsakoff syndrome.

Wernicke's encephalopathy, characterized by confusion, ataxia, and ophthalmoplegia, is an acute phase condition that occurs due to acute thiamine deficiency. Korsakoff syndrome follows as a chronic condition and involves profound amnesia and confabulation, often after Wernicke's symptoms have improved but without appropriate thiamine replacement.

Pyridoxine (B6), cobalamin (B12), and folate are important vitamins for various metabolic processes, including the synthesis of neurotransmitters and DNA synthesis, but they are not specifically linked to the neurological deficits that arise as a direct consequence of thiamine deficiency due to alcoholism. Thus, thiamine’s critical role in neurological health, especially in alcohol-dependent individuals, makes it the correct answer in this context.