Bone mineralization status measured by dual energy radiographic densitometry in preterm infants fed commercial formulas

We have studied the effect of two preterm commercial infant formulas with d ifferent calcium and phosphorus contents on the mineral balance and bone mi neralization of 30 preterm infants at 1 month of age. Bone mineralization w as measured by dual energy X-ray densitometry. The formula supplying a high er content of calcium and phosphorus promoted higher mineral retention (P < 0.01) as well as higher bone mineral content (1.556 vs, 1.073 g, P < 0.01) and bone mineral density (0.458 vs. 0.424 g/cm(2), P < 0.05), approaching values of the control group, which comprised a cohort of 15 preterm newborn s whose gestational age was 4 weeks older than the subjects selected to be fed with the formulas. The intake of calcium correlated with retention (r = 0.69); the phosphorus intake also correlated with phosphorus retention (r = 0.95), Intakes of calcium and phosphorus correlated with the bone mineral content (r = 0.65) and with bone mineral density (r = 0.49). We conclude t hat formulas for preterm infants should not have a calcium content lower th an 120 mg/100 kcal and should have a calcium/phosphorus ratio of about 2 to promote adequate bone mineralization. (C) 1998 Elsevier Science Ireland Lt d. All rights reserved.