Which dietary management is recommended for a baby with PKU?

• A. No restriction
• B. Low phenylalanine diet
• C. High phenylalanine diet
• D. Regular formulas without restriction

Answer: (B)

When a baby has PKU, the body cannot properly metabolize phenylalanine, so keeping phenylalanine intake very low is essential to prevent brain damage. The recommended approach is a low phenylalanine diet using specialized infant formulas or breast milk formulas that are reduced in phenylalanine and supplemented with tyrosine, which becomes essential because phenylalanine isn’t available to make tyrosine. This approach provides adequate calories and nutrients while preventing toxic buildup. Regular formulas without restriction or high phenylalanine diets would allow dangerous levels to accumulate, and having no restriction would fail to prevent neurodevelopmental harm.