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

The influence of stages of lactation on the mineral and trace elementconcentrations of breast milk collected from 20 healthy lactating women ina Nigeria population was investigated using instrumental neutron activationanalysis (INAA) and proton induced X-ray emission (PIXE) analysis. The breastmilk samples were divided into colostrum (day 1–5), transitional (day6–13) and mature milk (day 14–28). The result of the study showthat colostrum milk has a significantly higher mean concentration of Ca, Cl,Cu, Fe, Mg, Na and Zn than the transitional and mature milk. Furthermore,the mean concentrations of Fe, Mg, Na and Zn in transitional milk were foundto be significantly higher when compared with the mature milk. It was alsoobserved from the semi-log plot of the concentration of the elements againstdays of lactation that the concentration of all the elements decreased significantlythroughout the lactation period studied with Cu, Fe and Zn concentration showingthe greatest decline, particularly in the early stages of lactation.