Concentration of zinc, copper and metallocalorie ratio in bottle-milks prepared by poor urban families.

The concentration of zinc and copper and metallocalorie ratios were measured in samples of bottle-milks fed to infants from a poor urban settlement in Brasilia, Brazil. The bottle-milks fed to infants under 1 year of age from a sample of 40 families were analysed for zinc and copper. Zinc and copper concentrations ranged from 0.7 to 11.5 mg/l (mean 3.37) and from 0.09 to 1.47 mg/l (mean 0.43), respectively. The mean metallocalorie ratio was 1.26 mg/MJ (5.29 mg/1000 kcal) for zinc and 0.17 mg/MJ (0.73 mg/1000 kcal) for copper. Based on minimum recommendations for formulae, 55% of the bottle-milks had both zinc and copper concentrations below 3.2 and 0.4 mg/l, respectively. However, owing to added sugar and high caloric concentrations in the milk preparations, metal:calorie ratios were below the minimum recommendations in 72.5 and 62.5% of cases for zinc and copper, respectively. The variation in zinc and copper concentrations in the milks prepared by mothers/infant caretakers under unsupervized home conditions is wide. Owing to the low availability of zinc in cow's milk preparations, it is of concern that more than half the bottle preparations had zinc and copper concentrations/ratios below the minimum recommendations.