Trace element nutrition status and dietary intake of children with phenylketonuria

The trace element status (copper, iron, zinc, manganese, chromium, and selenium) of 20 dietetically treated phenylketonuric (PKU) children was assessed. Significantly higher intakes of copper (p = 0.002) and iron (p = 0.005) were noted in PKU children compared with their siblings. No significant differences were found for zinc, manganese, or chromium. Intake of selenium was significantly lower (p = 0.0001) in PKU children (8.4 +/- 3.9 micrograms/d) than in siblings (41.6 +/- 9.4 micrograms/d). Plasma and urine selenium and erythrocyte glutathione peroxidase activity (GSHpx) were significantly lower (p = 0.001) in PKU children (0.38 +/- 0.11 mumol/L, 58.0 +/- 34.5 nmol/d, and 14.2 +/- 5.5 U/g Hb, respectively) than in siblings (0.82 +/- 0.15 mumol/L, 165.2 +/- 49.4 nmol/d, and 22.7 +/- 5.2 U/g Hb, respectively). No differences were found in plasma and urine concentrations of other elements. Intake of selenium was significantly correlated with erythrocyte GSHpx (r = 0.87, p = 0.0001) and plasma selenium (r = 0.71, p = 0.0001) for the combined groups. The need and possible procedures, including dietary manipulation, for increasing selenium intake in PKU subjects are discussed.