THE CONCENTRATIONS OF COPPER AND ZINC IN HUMAN MILK A Longitudinal Study

Abstract. Vuori, E. and Kuitunen, P. (Department of Public Health Science and Children's Hospital, University of Helsinki, Helsinki, Finland). The concentrations of copper and zinc in human milk—a longitudinal study. Acta Pædiatr Scand, 68: 33, 1979.—Twenty-seven healthy Finnish mothers were followed during the course of their entire lactation period. A total of 229 individual milk samples, collected in the beginning and at the end of each feed during a 24-h period, were obtained from the 2nd week to the 9th month of lactation. The copper and zinc concentrations were determined by atomic absorption spectrophotometry. The concentrations of the trace-elements investigated were dependent on the stage of lactation. The median copper and zinc concentrations decreased during the course of lactation from about 0.60 mgyl and 4.0 mg/l to 0.25 mg/l and 0.5 mg/l, respectively. The importance of considering the stage of lactation in the evaluation of the trace-element nutrition value of breast milk should be emphasized. The calculated means of the concentrations of these trace-elements in mature human milk presented in the literature seem to overestimate the actual levels in prolonged lactation.