The importance of mineral supply in preterm infant nutrition

Abstract

Although human breast milk contains significant biomolecules with major impact on growth and development of preterm babies, a diet based exclusively on this milk over a longer period of time can be associated with the development of micronutrient deficiency in this sensitive group of infants. The aim of this study was to determine the content of micronutrients in human breast milk from the mothers of preterm infants and in infant formula, and the influence of mineral content on the osmolality and potential renal solute load. Human breast milk taken during the lactation period was examined, before and after frozen storage, pasteurization and supplementation with a fortifier, with mineral content being determined by inductively coupled plasma-optical emission spectrometry. Osmolality of preterm milk and infant formula was measured using an osmometer. During the lactation period of mothers of preterm born babies, the mineral content of the breast milk changed. The concentrations of all examined minerals differed in colostrum and in mature milk. However, there were no significant differences in mineral content in mature milk before and after pasteurization and storage. Supplementation of mature milk with a fortifier increased the concentration of minerals, the final osmolality and the potential renal solute load. The mineral content of mature milk was lower than necessary for the optimal growth of preterm infants, so adequate supplementation with a fortifier is needed to provide biologically important minerals. However, the osmolarity of supplemented milk should be monitored due to the potentially increased pressure on the kidneys of preterm infants.