The nurse is educating a parent after the birth of a newborn who is diagnosed with phenylketonuria (PKU). Which parent statement indicates teaching has been effective?

Choice A reason: PKU is caused by a deficiency of the liver enzyme phenylalanine hydroxylase, not an excess. This enzyme is needed to convert phenylalanine into tyrosine. Without it, phenylalanine accumulates and causes neurotoxicity. This statement reflects a misunderstanding of the condition. Choice B reason: Iron levels are not the focus of dietary management in PKU. While iron is important for growth and development, the primary concern is controlling phenylalanine intake through protein restriction. Low iron formula is not indicated unless there is a separate iron-related issue. Choice C reason: A low protein formula is essential for infants with PKU because phenylalanine is found in high-protein foods. Specialized formulas are designed to provide adequate nutrition while limiting phenylalanine intake. This statement demonstrates accurate understanding of dietary management. Choice D reason: Dietary restrictions for PKU are lifelong. Solid foods must also be carefully selected to avoid high phenylalanine content. The idea that restrictions end with solid food introduction is incorrect and potentially harmful.