Zinc and copper replacement during total parenteral nutrition.

A prospective study of zinc and copper replacement concurrently with total parenteral nutrition was undertaken during 29 courses of total parenteral nutrition in 20 tumor-bearing patients. Urinary excretion of zinc and copper was prospectively studied in eight of these subjects. While progressive declines in zinc and copper blood levels occurred in four unsupplemented control patients, maintenance of plasma trace metal concentrations within normal limits was accomplished by daily intravenous zinc and copper. A daily intravenous intake of 70 to 80 micrograms/kg of zinc and 60 to 65 micrograms/kg of copper were generally associated with normal blood levels and positive urinary balance of these trace elements. This study outlines a safe and effective zinc and copper replacement regimen in patients undergoing total parenteral nutrition.