Hair zinc and copper in Indonesian infants

The objective of this study was to determine the zinc and copper status in hair of a group of Indonesian infants aged 0-5 months, a period when growth faltering in this population is known to occur, and to determine the daily zinc and copper availability in the habitual diet. A mixed cross-sectional longitudinal design was used. Infants 0-3 months of age were recruited in two villages on the south coast of the island of Madura, Indonesia and followed up to the age of 5 months. All newborns during the study period were included. Hair samples were collected between the ages of 0 and 5 months at monthly intervals. Zinc and copper concentrations were determined by flame atomic absorption spectrophotometry and compared with a sample of Belgian controls, recruited cross-sectionally. Zinc and copper content of the habitual diet was calculated on the results of a food intake study previously performed in the same community. For the 42 Madurese infants recruited, 107 hair zinc and 96 hair copper concentrations were determined. Belgian infants (15 boys, 15 girls) served as controls. One Madurese infant died during the study and six moved from the area. Hair zinc concentrations were found to decrease with age in both populations, while the zinc and copper values did not differ from the Belgian controls. Hair zinc values were not correlated with growth performance. The boys had lower hair zinc values than did the girls. Copper values among the Indonesian infants did not show a trend over time; however, the Belgian children showed an increase towards the age of 12 months, although this was not significant. The mean daily zinc and copper availability in the habitual diet was less than half of the recommended daily allowance for adult women. The situation was much worse for lactating women given that the availability of these elements increased very little. The hair zinc and copper values indicate that they are not responsible for the early onset of linear growth retardation. The lower zinc values in boys might be an indication of a marginal deficiency. The very low zinc content of the diet consumed in this population could be an indication of a zinc and copper deficit in the Madurese population, although this needs to be confirmed.