9 All newborns (preterm and full-term) received enteral supplementation of vitamin D at a dose of 400 IU/day, which was maintained during the first two years of age. After discharge, the children were assessed monthly. During the study period, all infants were fed exclusively human milk. Children with indication for additive use received

a combined solution of calcium gluconate and dibasic calcium selleck kinase inhibitor phosphate between breast-feedings, which was maintained for the first six months of age (age corrected for the PTNs and chronological age for the FTNs), and complementary feeding was not introduced. All newborns were weighed on an electronic scale (Baby Model; Filizola – São Paulo, Brazil) and height was obtained using an anthropometric ruler graduated in centimeters. In the group of PTNs, serum calcium, phosphorus, and alkaline phosphatase measurements were performed

at the ages of 40 post-conceptual weeks and 6 months of corrected postnatal age. Furthermore, the concentration of calcium and phosphorus was determined in 6-hour urine samples between the third and fourth weeks of life (uncorrected age). In the group of FTNs, measurements of serum calcium, phosphorus, and alkaline phosphatase were performed only at 40 weeks post-conceptual age, as blood collection at 6 months was not approved by the Ethics Committee. Bone densitometry was performed at Volasertib in vivo the Laboratory for Bone Metabolism of Rheumatology, Faculdade de Medicina da USP. The following parameters Astemizole were evaluated: BMC, bone mineral density (BMD), and lean mass in three periods: 40 weeks of corrected post-conceptual age, as well as 3 and 6 months of corrected postnatal

age. BMC reflects the total amount of material (mineral bone) measured by absorptiometry, in grams; BMD is defined as bone mineral content divided by bone area in grams per square centimeter, and lean body mass is fat-free mass. A dual X-ray absorptiometry (DXA) apparatus was used (DXA: Discovery A; Hologic Inc. – Bedford, MA, USA) with the Infant Whole-Body scanning mode (software version 12.3.3; Hologic Inc.). The software used is considered superior to pediatric software for the analysis of bone mineral, accurately validated for both PTNs and FTNs.17 In addition, the fan-beam technique, used in the study, makes the Discovery A scanner more accurate when compared to the prior pencil-beam technique.18 The study by Blake et al. demonstrated that the Discovery A scanner has additional advantages, as it requires a lower radiation dose when compared to the previously used Discovery W (Hologic Inc. – Bedford, MA, USA) and QDR 4500 Hologic Inc. – Bedford, MA, USA) models. For a newborn, the effective radiation dose is 8.9 mSv for the whole body, and it is 7.5 mSv for a child aged 1 year.19 Examinations were performed without sedation after breastfeeding. The coefficient of variation for whole body BMD was 0.004 g/cm2 (0.4%), and the minimum significant difference for newborns evaluated in the study was 1.