Chronic use of alcohol can contribute to thiamine deficiency by which mechanism?

• A. Impaired absorption and utilization of thiamine
• B. Increased thiamine synthesis
• C. Increased thiamine storage in liver
• D. Enhanced thiamine absorption in the gut

Answer: (A)

Chronic alcohol use leads to thiamine deficiency mainly by disrupting how thiamine is absorbed and how it is used in the body. Alcohol damages the intestinal lining and interferes with the transport of thiamine into the bloodstream, so less thiamine enters circulation. It also impairs the liver’s ability to take up thiamine and convert it to its active form, thiamine pyrophosphate, which is needed by enzymes that drive carbohydrate metabolism. With reduced absorption and impaired activation, tissues don’t get enough functional thiamine, increasing the risk of deficiency. Therefore, impaired absorption and utilization best explains the mechanism. The other options aren’t supported because alcohol does not increase synthesis or storage of thiamine, nor does it enhance gut absorption; it tends to do the opposite.