Which nutrition support increases metabolic demand for thiamin?

• A. Enteral nutrition with high fat
• B. Parenteral nutrition due to the glucose load
• C. PN with amino acids only
• D. Oral hydration

Answer: (B)

Thiamin is a cofactor for enzymes that convert carbohydrates into energy, including pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase. When a large glucose load is delivered, as in parenteral nutrition with high dextrose, carbohydrate metabolism speeds up, which increases the body's thiamin requirements. Providing glucose through parenteral nutrition thus raises metabolic demand for thiamin more than other supports. The other options don’t impose the same heavy carbohydrate burden: high-fat enteral formulas deliver less glucose, amino-acid–only PN provides little carbohydrate, and oral hydration isn’t a meaningful energy source.