Nutritional Balance Studies in Very-Low-Birth-Weight Infants: Enhanced Nutrient Retention Rates by an Experimental Formula

Abstract

An experimental infant formula developed to meet the specific nutritional needs of very-low-birth-weight infants was evaluated by 96-hour balance studies in ten preterm infants (birth weight: 1,130 to 1,530 gm). The formula contained 23.2 gm/liter of protein (whey protein/casein ratio, 60:40), 44.1 gm/liter of fat (50% medium-chain triglycerides) and 85.0 gm/liter of carbohydrate (50% lactose, 50% Polycose), and provided relatively higher amounts of calcium, phosphorus, vitamin D, and electrolytes than are in human milk. All infants were fed 150 ml/kg/day (120 calories/kg/day) by intermittent gavage. Balance studies were carried out nine days following establishment of oral intake. The mean (±SEM) nutrient retention rates revealed by balance studies in these infants (calcium, 170 ± 4 mg/kg/day; phosphorus, 78 ± 3 mg/kg/day; nitrogen, 426 ± 8 mg/kg/day; sodium, 1.4 ± 0.1 mEq/kg/day) were comparable to normal fetal accretion rates. The mean (±SEM) fat absorption was 92.5 ± 0.9%. No clinical intolerances or biochemical abnormalities were observed, and adequate postnatal growth was achieved in all infants. The diet proved to be nutritionally advantageous and safe for very-low-birth-weight infants.

Rickets in a Very Low Birth Weight Infant

“…Moreover, weight gain between the 20th and 62nd day of life appeared appropriate at II g/kg/day. Studies indicate that specialized preterm infant formulas promote mineral retention and bone mineralization at intrauterine rates (12)(13)(14). In this infant mineral retention but not bone mineralization appeared adequate.…”

Hypercalciuria in Premature Infants Receiving High Mineral‐Containing Diets

“…These studies and bone density studies demonstrating hypomineralization in human milk-fed infants have led to the routine practice of fortifying human milk with Ca and P or providing special formulas with relatively high levels of these minerals (23). Improved mineral balance has been shown in numerous balance studies of infants receiving fortified human milk or formulas designed for premature infants (1,(10)(11)(12)(13)(14)(15)(16)(17)(18).…”

Evaluation of Liquid or Powdered Fortification of Human Milk on Growth and Bone Mineralization Status of Preterm Infants

“…Thus, unsupplemented PHM lacks sufficient levels of calcium and phosphorus to support bone growth and mineralization. Previous studies of preterm infants fed unsupplemented breast milk concluded that consumption of inadequate levels of calcium and phosphorus may predispose the VLBW infant to osteopenic changes, rickets, and fractures (15)(16)(17)(18)(19)(20)(21)(22)(23).…”