Daily dietary intake of copper, zinc, and selenium of exclusively breast-fed infants of middle-class women in Burundi, Africa.

Abstract

Copper (Cu), zinc (Zn), and selenium (Se) in human milk of middle-class Burundian women during the first 10 mo of lactation have been determined. Wet acid digestion, using nitric and perchloric acids, and atomic absorption spectrometric analysis have been used. Daily intakes have been calculated and proven to decrease from 0.39 +/- 0.05 (colostrum) to 0.16 +/- 0.02 (mature milk), 2.3 +/- 0.3 (colostrum), to 1.2 +/- 0.2 mg (mature milk) and 10.9 +/- 1.5 (colostrum) to 5.3 +/- 0.8 micrograms (mature milk) for Cu, Zn, and Se, respectively. Since values for this African country are nonexistent, intake levels are compared with literature data and found to be somewhat higher than those observed in other poorly nourished countries. The recommended safe and adequate daily intake for infants of 0-6 mo of age, as proposed by the National Research Council of the USA, is only met for Burundian infants < 1 mo of age. The function of copper (Cu) and zinc (Zn) as essential trace elements has been known for quite a number of years (1). Also, selenium (Se) is a trace element essential for the activity of glutathione peroxidase (2) and type I iodothyronine 5-deiodinase (3). For all three elements, an adequate intake is necessary for satisfactory infant growth and development (4). In view of the almost total lack of relevant data on Burundi (Africa), we have determined Cu, Zn, and Se in human milk of middle-class Burundian women during the first 10 mo of lactation (5). The aim of this study is to assess infants' elemental intake for this country and compare this with literature data on trace elemental intake of exclusively breast-fed infants.