Nutrient balance, metabolic response, and bone growth in VLBW infants fed fortified human milk

Abstract

The effects of fortification of preterm human milk were evaluated by comparing two groups of very low birth weight infants (birth weight < or = 1300 g, gestational age < or = 30 weeks): six fed preterm human milk fortified with a commercially available protein-mineral supplement (protein 0.7 g/dl, calcium 90 mg/dl, phosphorus 45 mg/dl) and seven fed unfortified preterm human milk. Nitrogen and energy balance studies were performed at an average age of 56 postnatal days. Nitrogen retention in the fortified group (348.2 +/- 70.5 mg/kg/day) was significantly greater than that in the unfortified group (196.0 +/- 50.0 mg/kg/day) and similar to that of fetuses of comparable gestational age. Energy stored by the two groups did not differ. At age 8 weeks, the infants in the fortified group had higher serum protein, higher serum albumin, and better mineral status (higher serum calcium and phosphorus and lower alkaline phosphatase and renal tubular reabsorption of phosphate). The bone density and width of the distal third radius, as measured by X-ray microdensitometry, were greater in the fortified group than in the unfortified group 12 weeks after birth. These results suggest that the supplement corrects any nutritional inadequacies of preterm human milk for very low birth weight infants.