Zinc and copper requirements during parenteral nutrition in the newborn.

Zinc and copper requirements and metabolism in surgical neonates on parenteral nutrition were monitored. Without a supplementation of zinc, the plasma zinc level decreased in the second week and became severe with time. In full-term babies, for up to 4 weeks of parenteral nutrition, 40 micrograms/kg/d was adequate to maintain the plasma zinc level within a normal range. For extended periods of parenteral nutrition, the dose of zinc can be reduced without excess loss of this mineral. However, premature babies in the zinc-supplemented group showed a decreased zinc level in the fourth week of parenteral nutrition, indicating that 40 micrograms/kg/d of zinc supplementation was inadequate for premature surgical babies. Infants with enterostomy require increased amounts of zinc, even up to 300 micrograms/kg/d. Copper levels revealed little change, up to 4 weeks of this feeding. In the presence of increased fluid loss through gastrointestinal fistulas, deficiency of copper occurred and the copper requirements increased. Careful monitoring is necessary to ensure an adequate supply of these minerals to surgical neonates.