Variations in trace element concentrations in breast milk with stages of lactation

The influence of stages of lactation on the mineral and trace element conce ntrations of breast milk collected from 20 healthy lactating women in a Nig eria population was investigated using instrumental neutron activation anal ysis (INAA) and proton induced X-ray emission (PIXE) analysis. The breast m ilk samples were divided into colostrum (day 1-5), transitional (day 6-13) and mature milk (day 14-28). The result of the study show that colostrum mi lk has a significantly higher mean concentration of Ca, Cl, Cu, Fe, Mg, Na and Zn than the transitional and mature milk. Furthermore, the mean concent rations of Fe, Mg, Na and Zn in transitional milk were found to be signific antly higher when compared with the mature milk. It was also observed from the serni-log plot of the concentration of the elements against days of lac tation that the concentration of all the elements decreased significantly t hroughout the lactation period studied with Cu, Fe and Zn concentration sho wing the greatest decline, particularly in the early stages of lactation.