The Effects of Low and High Dose Oral Calcium and Phosphor Supplementation on Nephrocalcinosis Diagnosed by Sonography in Premature and Low Birth Weight Neonates

Nephrocalcinosis is defined as calcium deposition in the renal interstitium. One of the major causes of neonatal nephrocalcinosis is the use of calcium and phosphor supplements for premature neonates. This study aims at assessing the effects of calcium and phosphor supplementation in neonatal nephrocalcinosis by renal ultrasonography. In this randomized controlled trial, 37 premature neonates with birth weights < 1500 g or a gestational age of < 34 weeks were considered. Two different doses of calcium 75 vs. 230 mg/kg/day and phosphor 50 vs. 110 mg/kg/day were prescribed and laboratory and sonographic data were then documented and evaluated. The incidence of nephrocalcinosis was 47.8% in group 1 and 28.6% in group 2. There was a significant association between NC and positive family history of renal stones, shorter duration of TPN and NICU stay. The amount of calcium dosage, gestational age, birth weight, sex, use of surfactants, and mechanical ventilation did not have any significant association with NC. In this study, the neonates with NC were mostly the white flake type (8 cases) and the majority of the lesions were 1-2 mm. All the lesions were located in the pyramid and papilla areas, acoustic shadows were not prevalent and stones were not observed in any of the patients.