Zinc and copper replacement during total parenteral nutrition

Area of Science:

• Oncology
• Nutritional Science
• Trace Element Metabolism

Background:

• Total parenteral nutrition (TPN) can lead to deficiencies in essential trace elements like zinc and copper.
• Tumor-bearing patients may have altered trace element requirements or metabolism.
• Monitoring and appropriate supplementation are crucial for patients on long-term TPN.

Purpose of the Study:

• To evaluate the efficacy and safety of concurrent zinc and copper replacement during TPN in tumor-bearing patients.
• To determine optimal intravenous dosages of zinc and copper for maintaining normal plasma levels.
• To assess the impact of supplementation on urinary excretion and overall trace element balance.

Main Methods:

• Prospective study involving 29 TPN courses in 20 cancer patients.
• Administration of daily intravenous zinc and copper to supplemented patients.
• Monitoring of plasma zinc and copper levels.
• Measurement of urinary zinc and copper excretion in a subset of patients.
• Comparison with unsupplemented control patients.

Main Results:

• Daily intravenous zinc (70-80 µg/kg) and copper (60-65 µg/kg) effectively maintained plasma trace metal concentrations within normal limits.
• Unsupplemented patients showed progressive declines in zinc and copper blood levels.
• Supplemented patients generally exhibited normal blood levels and positive urinary balance for these elements.
• The replacement regimen was found to be safe.

Conclusions:

• Concurrent intravenous zinc and copper supplementation is a safe and effective strategy for preventing trace element deficiencies in cancer patients receiving TPN.
• Established daily intravenous dosages can maintain adequate zinc and copper levels, supporting positive mineral balance.
• This regimen addresses a critical nutritional support need in oncology patients.