What is the typical dietary management for chronic PKU?

• A. Phenylalanine-Free Diet With Tyrosine Supplementation
• B. Tyrosine-Free Diet With Phenylalanine Supplementation
• C. High Phenylalanine Diet
• D. Normal Diet

Answer: (A)

Phenylketonuria limits the body's ability to convert phenylalanine into tyrosine, so phenylalanine can build up and harm brain development if not controlled. The goal of management is to minimize phenylalanine intake while ensuring enough tyrosine for normal growth and function, since tyrosine becomes an essential amino acid in PKU. This is achieved by a phenylalanine-free diet supported with a tyrosine-supplemented, phenylalanine-free medical formula or carefully chosen low-phenylalanine foods. Diets that add phenylalanine, or that omit tyrosine, would not prevent the harmful buildup and could worsen outcomes, while a normal diet would not control phenylalanine levels.