Estimating the oligoelement requirements of children subject to exclusively parenteral nutrition by means of neutron activation analysis

Because of the rich and varied food he eats, deficiencies in oligoelements of dietary origin are very rarely found in man. However, several cases of zinc and copper deficiency have been reported in adults and children subject to prolonged entirely parenteral nutrition. In the present case ten children (eight infants of less than 18 months and two children aged between 2 and 8 years) fed exclusively by intracardiac catheter on a reconstituted diet were studied. The serum concentrations of copper, manganese, selenium and zinc in the children fed on this artificial diet were measured by neutron activation and gamma spectrometry, both with and without chemical separation. The values obtained in the young patients and in controls of the same age were compared. The result of these comparisons and a study of the kinetics of serum concentrations in the patients (one analysis every 20 days for 90 days) enabled us to determine that there was a balanced intake of copper, an excess of manganese and a considerable deficiency in zinc and selenium. In view of these observations, the diet was modified and it was established that the serum oligoelement content followed changes in oligoelement intake. Thus the serum concentrations of selenium and zinc were restored in a few weeks - completely in the case of selenium with an intake three times higher (3 μg/kg/24 h) and incompletely in the case of zinc with the intake doubled (50 μg/kg/24 h). On the basis of these results and kinetic data on the mineral metabolism, we have been able to estimate the copper, manganese, selenium and zinc requirements of children undergoing parenteral nutrition. (author)