Trace elements in human milk.

Presented is a study, using multielement neutron activation analysis, of the elemental composition of blood plasma and milk in a group of lactating Australian women. Having established baseline values for nine elements, the authors studied factors affecting concentrations in milk and the partitioning of those elements between plasma and milk. Changes in this partitioning with the progression of lactation were demonstrated, and their nutritional implications for the exclusively breast-fed baby discussed. Progestogen-only oral contraceptives had no significant effect on levels of any of the trace elements in either blood or milk.