Measurement of zinc and copper levels in breast milk.

Zinc and copper levels in breast milk were measured to assess the accuracy of the analysis and to obtain a range of values for the local population. Samples were collected 7 days after delivery from 48 well-nourished mothers who had given birth to healthy full-term infants. The method was found to be accurate and reproducible provided precautionary measures were taken to avoid sample contamination. A wide variation in values was found in samples from different mothers, however, ranging from 155 to 680 microgram/dl for zinc and from 27 to 90 microgram/dl for copper.