Copper, zinc and selenium concentrations in milk from middle-class women in Burundi (Africa) throughout the first 10 months of lactation

Copper, zinc and selenium were measured in a total of 47 samples of human milk from five middle-class women from Burundi, Africa. Milk samples were taken from day 2 after delivery to 10 months postpartum. Copper and zinc were analyzed by flame atomic absorption spectrometry, while a hydride generation mode was used for selenium. The average copper concentration declined from 0.59 ± 0.01 μg ml−1 at day 2 to 0.08 ± 0.04 μg ml−1 after 10 months of lactation. Zinc levels decreased from a mean of 3.8 ± 0.5 μg ml−1 to 0.75 ± 0.02 μg ml−1 after 10 months. For selenium, the concentration at day 2 (15.2 ± 2.3 ng ml−1) declined only after 2 weeks to a value of 5.2 ng ml−1 10 months postpartum. For copper a diurnal variation was observed. Compared to literature data, copper and zinc levels in Burundian women proved to be in the normal range, while selenium concentration levels were at a lower level.