NUTRITION STUDIES IN TREATED INFANTS AND CHILDREN WITH PHENYLKETONURIA - VITAMINS, MINERALS, TRACE-ELEMENTS

Chemically defined or elemental medical foods provide the majority of protein equivalent in the diets of children treated for phenylketonuri a (PKU), Because of the restricted intake of high biologic value prote in, children with PKU often have lower than normal plasma concentratio ns of ferritin and zinc. Few reported studies are available on vitamin status of children with PKU undergoing treatment. This report address es intakes of iron, zinc and vitamin A and their plasma concentrations in children ingesting either a low phenylalanine (Phe) casein hydroly sate or a Phe-free L-amino acid mix, With significantly greater than r ecommended mean intakes of iron and low to recommended mean intakes of zinc, individual plasma ferritin concentrations were often in the def icient (< 12 ng/ml) or marginal (12 < 20 ng/ml) range; plasma zinc con centrations were usually normal when patients received an L-amino acid mix, When L-amino acids were the source of protein equivalent for inf ants, 48% of plasma retinol concentrations were in the marginal (20 < 30 mu g/dl) or deficient range (< 20 mu g/dl) in spite of most vitamin A intakes being greater than Recommended Dietary Allowance for age. S ome hypothetical reasons for low concentrations of plasma ferritin and retinol are discussed.