Influences Of Different Feeding Patterns On Vitamin D And Bone Mineralization Level Of Very Preterm Infants

Objectives:The aims of this study were to compare the level of 25-hydroxyvitamin-D [25(OH)D] and the level of bone mineralization in blood in very preterm infants at birth and at 35 weeks of corrected gestational age; and to explore the influence of different feeding patterns on bone health in very preterm infants.Methods:In accordance with the inclusive and exclusive criteria,36 very preterm infants born in Women’s Hospital affiliated of Zhejiang University were enrolled and divided into two groups from June,2015 to November,2015:formula feeding group (n=16)and breast feeding group (n=20).The very preterm infants in formula feeding group were mostly fed with formula,(the volume of breast milk was less than 50% of total milk).Those in breast milk group were mostly fed with breast milk (the volume of breast milk was more than 50%). Human milk fortifier was added in breast feeding group, when the volume of milk varied form 50-100ml/kg/day. The level of parathyroid hormone (PTH) and 25(OH)D in blood of both groups were measured by electrochemluminescenceimmunoassay at birth (from umbilical cord) and at 35 weeks of corrected gestational age (from vein).The total levels of calcium, phosphorus, ALP in blood of two groups were measured at 1-2 days after birth and 35 weeks corrected gestational age (both from vein). Moreover, the weight, height and head circumference in both groups were corrected every week after birth to explore the influence of different feeding patterns in very preterm infants on developments. All data were compared with the software of SPSS 20.0 for windows, A p value<0.05 was considered statistically significant.Results(1). There were no significant difference in the level of 25(OH) D at birth [25.30(20.13) ng/ml vs 26.00(7.96) ng/ml and at 35 weeks of corrected gestational age(21.60(8.46)ng/ml vs 23.48(10.35)ng/ml] between the two groups. There were also no significant difference in the proportion of 25 (OH) D(?)20ng/ml between the groups at birth (5%vs 12.5%) and at 35 weeks of corrected gestational age (45%vs37.5%).(2). The level of ALP was higher in breast feeding group than that in formula feeding group (318.0(164) U/L vs.229.5(110) U/). However, the duration of parenteral nutrition was relatively shorter in breast feeding group than that in formula feeding group (17.0(7)d vs.21.5(6)d).(3). There were no significant differences in the growth of the very preterm infants at 35 weeks of corrected gestational age (P>0.05)Conclusion(1). The indeficiency of vitamin D is not significant among very preterm infants at birth. And the VD level in blood at 35 weeks of corrected gestational is lower compared to the VD level in blood at birth. Different feeding pattern, has no significant influence on vitamin D levels.(2). The formula milk group has longer duration of parenteral nutrition and it may have lower risk of metabolic bone disease, according to growth of ALP in blood.(3). Feeding pattern has no significant influence on the development of very preterm infant at 35 weeks of corrected gestation.