[Dynamics of biometal distribution in breast milk]

The results of 352 atomic-absorption measurements of the concentrations of 8 basic biometals in breast milk samples from women of different age were investigated by variation-statistical and correlative analysis. It was found that in all the cases the distribution patterns of biometals were asymmetric. K, Na, Fe and Mn were marked by logarithmic distributions, whereas Ca, Mg, Zn and Cu by power distributions with the index 1/2. That was determined most likely by the physicochemical nature of the mechanisms by which milk homeostasis was controlled. It was shown that in assumption about the normal distribution pattern, commonly accepted in practice, might lead to noticeable errors in quantitative assessments and to erroneous qualitative conclusions. The most probable concentrations of the metals and the width of their distribution showed alterations in time, dissimilar for different metals, including extremal alterations, with the concentrations of the test metals changing 1-5-fold and elementary relations up to 10-fold. For K-Na, Fe-Mn, Zn-Cu and Fe-Cu pairs the interelementary relations of the presumably biochemical nature were discovered, with the stability of those relations being dependent on the time of lactation. The data on variations in the balance of biometals can be used in the design of improved substitutes of breast milk and formula feeding adapted to babies of different age.