What is the treatment for PKU?

• A. A high-phenylalanine, low-tyrosine diet
• B. A phenylalanine-restricted, tyrosine-supplemented diet
• C. A low-fat, high-carb diet
• D. A standard balanced diet with no restrictions

Answer: (B)

PKU arises when the body can’t convert phenylalanine to tyrosine, so phenylalanine builds up and can harm brain development. The treatment is to limit phenylalanine in the diet while making sure the person still gets enough protein and all other nutrients by providing tyrosine since it becomes essential. This is done with a phenylalanine-restricted diet and tyrosine supplementation, often using specialized medical foods that supply other amino acids without phenylalanine. A high-phenylalanine diet would worsen the condition, a low-fat, high-carb plan doesn’t address the metabolic defect, and a standard unrestricted diet fails to prevent harmful phenylalanine accumulation.