Supplementation of mothers' milk for preterm infants: Mineral bioavailability

Abstract

<p>Use of multi-nutrient supplements for preterm infants fed mother's milk is common practice in neonatal intensive care units to provide sufficient amounts of minerals and other nutrients. The research delineated in this thesis investigated calcium, magnesium, zinc and iron bioavailability from supplemented mother's milk for preterm infants. Multi-nutrient supplementation to mother's milk had the benefit for preterm infants of achieving short-term growth rates parallel to the fetus of similar gestational age without reducing the dietary bioavailability of calcium, magnesium and zinc. In the infant-piglet model it was demonstrated that the addition of calcium and phosphorus to the diet in similar proportions as to preterm infants fed fortified mother's milk did not reduce iron bioavailability. Multi-nutrient supplementation to mother's milk did not result in better short- or long-term growth, greater whole body bone mineral content or better zinc status in comparison to supplementation with calcium and phosphorus alone. If it is, however, desirable for the preterm infant to attain short-term growth rates similar to the intrauterine fetus of the same post-menstrual age, future investigations should address the impact of multi-nutrient supplementation on the bioavailability of other minerals important for growth and development. Long term outcomes of whole body bone mineral, lean and fat mass and zinc status appeared to be determined by post-hospital discharge nutrition rather than nutrition in early neonatal life. Growth and body composition of breast-fed premature infants in the first year of life followed a different pattern in comparison to preterm infants fed a standard term formula. Therefore, future investigations should establish appropriate references for growth and body composition derived from breast-fed term infants in order to evaluate these outcomes in preterm infants fed mother's milk. The research described in this thesis has contributed to the concept that moderate nutrient and mineral intakes from mother's milk supplemented with a multi-nutrient fortifier or from mother's milk alone with only supplemental calcium and phosphorus may be appropriate for the healthy preterm infant even though current nutrient recommendations are not met. Based on the information provided in this thesis, functional responses to mineral nutrition should be considered in setting nutrient recommendations for preterm infants.</p>