Zinc balance in malnourished children given prolonged total parenteral feeding

Zinc balances were performed in five different occasions in three children receiving prolonged total parenteral nutrition (TPN) for 4 or more weeks. Excessive urinary zinc loss was a constant finding and one patient also presented increased fecal loss. It is concluded that TPN solutions when administered for long periods must be supplemented with zinc in order to obtain positive balances and a retention of zinc between 50-100 micrograms kg/day. In children without abnormal losses supplements recommended by the American Medical Association (100 micrograms/kg/day up to 5 years and from 2.5 to 4 mg/day in old children) seem adequate. In case of deficit in Zn and/or high digestive losses supplement of Zn in TPN must be increased up to 200 to 500 micrograms/kg/day.