Serum level of vitamin D in preterm infants and its association with premature-related respiratory complications: a case-control study

Abstract

Background and aimPrematurity and related problems, especially respiratory distress, are one of the main challenges for neonatal medicine. The aim of this study was to compare vitamin D levels in preterm infants with, and those without respiratory distress.MethodsThis case-control study was conducted in Ghaem and Emam Reza Hospitals in Mashhad (Iran) from 2015 to 2016. In this study, we examined 160 preterm infants weighing less than 2000 grams and born at less than 34 weeks’ gestation. Serum vitamin D levels were measured in preterm infants without- and those with respiratory distress, and their mothers. Neonatal characteristics, including age, sex, birth weight, gestational age, Apgar score and needs for oxygen, resuscitation, ventilation and surfactant were documented. The data were analyzed using SPSS version 16.0.ResultsMeans serum level of maternal vitamin D in control and case groups were 16.66±14.29 ng/dl and 21.23±15.19 ng/dl, respectively (p=0.029). In addition, mean serum level of neonatal vitamin D in control and case groups were 11.69±8.66 ng/dl 17.9±12.55 ng/dl, respectively (p=0.001). Vitamin D levels in premature neonates without respiratory distress and their mothers were significantly different from other preterm neonates with respiratory distress (p=0.029). There was a direct correlation with neonatal and maternal vitamin D levels (r=0.713, p=0.001). The duration of hospitalization (p=0.001), gestational age (p=0.073), birth weight (p=0.001), one- and (p=0.001) five-minute (p=0.001) Apgar scores and head circumference (p=0.002) had significant relation with vitamin D levels in neonates. Death (12.5%) and pneumothorax (7.5%) were the main complications among cases with respiratory distress.ConclusionAccording to the results of present research, neonatal vitamin D levels have a significant association with respiratory distress syndrome and maternal vitamin D levels.

Comparison of Serum Vitamin D in the Umbilical Cord of Survived with Not Survived Premature Infants

“…In a study by Choi et al, there was a significant relationship between infants born in the second trimester of pregnancy and severe vitamin D deficiencies compared to third-trimester neonates (26). Studies have shown that most vitamin D from the mother reaches the neonate in the last weeks of pregnancy (13).…”

“…Although the main cause of this association was not determined, several studies have shown the role of vitamin D in other problems of premature newborns. Boskabadi et al found that vitamin D levels were lower in preterm infants with respiratory problems (13). Because respiratory problems are one of the most common causes of hospitalization of premature newborns and their mortality, vitamin D deficiency may be effective in increasing the risk of death in premature newborns.…”

“…In a study of 44 infants born before the 29th week of gestation, the average vitamin D level of the umbilical cord blood was 33.8 ng/mL in 41 survived neonates and 30.4 ng/mL in 3 dead neonates, and there was a significant difference between the two groups in the vitamin D level (14). Several studies have shown that respiratory distress, intraventricular hemorrhage, retinopathy of prematurity, and infections are more common in newborns with vitamin D deficiency (12,13). On the other hand, the problems regarding neonatal morbidity and mortality have important effects.…”

“…Vitamin D deficiency is common in premature neonates (12). which can be due to maternal vitamin deficiency and causes serious problems in premature neonates, such as increased risk of respiratory problems at birth, osteopenia of prematurity, bronchopulmonary dysplasia, increased risk of infectious diseases, reduced brain growth, seizures, growth disturbances, retinopathy of immaturity, brain hemorrhage, and death (13)(14)(15). Studies report the effect of vitamin D deficiency on the regulation of immune responses by generating an antimicrobial peptide pattern in epithelial cells, neutrophils, and macrophages and the lack of lung maturation by examining the specific vitamin D receptor (VDR), which is expressed in most tissues of the body, in terms of regulation, diagnosis, and differentiation of the cell in immature died premature neonates (15)(16)(17)(18)(19)(20).…”

“…Studies report the effect of vitamin D deficiency on the regulation of immune responses by generating an antimicrobial peptide pattern in epithelial cells, neutrophils, and macrophages and the lack of lung maturation by examining the specific vitamin D receptor (VDR), which is expressed in most tissues of the body, in terms of regulation, diagnosis, and differentiation of the cell in immature died premature neonates (15)(16)(17)(18)(19)(20). Therefore, deficiency of this vitamin is one of the main challenges in the care of neonates (13).…”