American Journal of Clinical Nutrition, Vol 26, 744-749, Copyright © 1973 by The American Society for Clinical Nutrition, Inc.

Copper metabolism in young women fed two levels of copper and two protein sources

¹ Associate Professor of Nutrition, Department of Food and Nutrition, University of Maryland, and Maryland Agricultural Experiment Station
² Madison, Wisconsin

Ten healthy young women consuming the same diets except for protein sources, in a crossover experimental design, had higher average intakes of copper when consuming peanut flour, 4.355 mg, than eating casein-lactalbumin, 3.900 mg. No significant differences in the group average retention or percent apparent absorption was evident due to the different protein sources. A trend of a higher percent apparent absorption and lower fecal copper on the casein-lactalbumin than the peanut flour diet was evident.

All individuals appeared to be in positive copper balance, However, when a correction of 70 µg was made for sweat losses under the moderate climatic conditions of this study, two subjects on the peanut flour diet were in equilibrium rather than in positive balance. If this investigation had been carried out under warm or hot climatic conditions, three subjects would have been in negative copper balance because sweat losses would be higher, i.e., approximately 1.0 mg/day.

This study indicates that a copper allowance of 4.5 to 5.0 mg is needed to cover the requirements of all healthy young women, depending on climatic conditions.