Phenylketonuria diet in adolescents--energy and nutrient intake--is it adequate?

The age at which phenylalanine (PA) restricted diet can be safely terminated in phenylketonuria (PKU) children has been the subject of discussion but a recent United States collaborative study has provided data showing that blood PA level should be kept below 10 mg/dl at least through adolescence. This presents nutritional problems in providing an adequate diet to meet the adolescent growth spurt in the absence of reliable information on the nutrient requirements of PKU adolescents. The problem is complicated by the emotional development of adolescence presenting compliance difficulties. The use of a computer programme to calculate nutrient intake and appropriate amino acid restricted diets for adolescents is described. It has been shown using the computer programme that an amino acid mixture specially adapted for use by adolescents is needed to provide sufficient vitamins, minerals and trace elements. Nutritional deficiency in adolescent PKU children may be a factor contributing to developmental abnormality.