Severe vitamin D deficiency in preterm infants: possibly no association with clinical outcomes?

Risk factors associated with vitamin D deficiency in preterm neonates: a single-center step-wise regression analysis

BACKGROUND

Vitamin D deficiency is particularly concerning in pregnant women, leading to various health-related issues in mothers and their babies, especially those born prematurely, including neonatal skeletal and respiratory disorders. In addition, there have been several reports indicating the presence of multiple impactful factors in the development of vitamin D deficiency. Therefore, we aimed to evaluate the vitamin D level in very preterm and moderately preterm newborns and investigate its association with presumed influential factors.

METHODS

This cross-sectional descriptive study was performed on 54 mothers and their preterm neonates with gestational ages less than 34 weeks at delivery (i.e., very preterm and moderately preterm). After the serum vitamin D levels were determined from samples obtained in the first 24 h after birth, the babies were divided into two groups based on the presence or absence of deficiency. The relationship between several factors and the neonatal serum vitamin D level was investigated separately and in a linear step-wise regression model.

RESULTS

The differences between the groups regarding maternal age, gestational age, neonate's gender, birth weight, and delivery method with neonatal vitamin D levels were not statistically significant. However, maternal vitamin D levels strongly correlated with neonatal vitamin D levels (P-value < 0.001, r = 0.636). The regression model also yielded a strong predictive capability (P-value < 0.001, Adjusted R² = 0.606), with the maternal vitamin D level demonstrating a significant impact.

CONCLUSIONS

Low vitamin D levels in pregnant mothers correlate with deficient levels in their preterm neonates. Therefore, as vitamin D deficiency significantly affects both the mother's and newborn's health, it is recommended that healthcare providers provide comprehensive plans for vitamin D supplementation during pregnancy.

The association of serum vitamin D level and neonatal respiratory distress syndrome

BACKGROUND

Neonatal respiratory distress syndrome (NRDS) is a critical disease in premature infants. Vitamin D plays an important role in promoting the development of fetal lung structure and the formation of pulmonary surfactants. This study aimed to investigate the correlation between the serum 25(OH)D₃ level in the cord blood of premature infants and the prognosis of NRDS.

METHODS

This retrospective study recruited 82 preterm infants (gestational age 28-36 weeks) diagnosed with NRDS as the NRDS group, and 82 non-NRDS preterm infants as the control group, respectively. The diagnostic efficiency of 25(OH)D₃ on NRDS was revealed by receiver operating characteristics curve (ROC) analysis. Enzyme linked immunosorbent assay (ELISA) was performed to evaluate the 25(OH)D₃ level in the serum of the cord blood in preterm neonates. The NRDS risk indicators were identified by the multivariate logistic regression analysis.

RESULTS

Cord blood 25(OH)D₃ levels were significantly lower in NRDS preterm infants than control group infants. 25(OH)D₃ levels in cord blood can be used to predict NRDS in preterm infants. In addition, 25(OH)D₃ levels in cord blood were positively correlated with Apgar score (1 min/5 min) and negatively correlated with oxygen support/CPAP duration in preterm infants with NRDS. 25(OH)D₃ in cord blood <57.69 nmol/L (24 ng/ml), gestational age <31 weeks, birth weight <1.86 kg, Apgar score (1 min) <7 and Apgar score (5 min) < 8 were independent risk factors for NRDS.

CONCLUSION

25(OH)D₃ level is an independent risk factor for NRDS in preterm infants.

Evaluation of Maternal and Infantile Levels of Vitamin D in Preterm Infants

INTRODUCTION

Vitamin D deficiency is highly prevalent during pregnancy and in premature infants. This study was done to investigate the maternal and infantile levels of vitamin D in preterm infants.

METHODS

Using available sampling during 2018-2020, the maternal and umbilical cord serum levels of vitamin D were measured in 294 premature infants in Ghaem Hospital, Mashhad, Iran. A researcher- made questionnaire consisting of neonatal demographic and clinical characteristics was used as the data collection tool. Both maternal and placental vitamin D levels were categorized into four classes: severe deficiency (vitamin D<10 ng/ml), moderate deficiency (10.1≤vitamin D≤20 ng/ml), mild deficiency (20.1≤vitamin D≤30 ng/ml) and normal (vitamin D >30.1ng ml).

RESULTS

Vitamin D deficiency was seen in 89% of premature infants (46.6% severe, 30.6% moderate, and 11.9% mild). Serum levels of vitamin D were 18.28±13.94 ng/ml and 14.10±9.70 ng/ml in mothers and infants, respectively. The infants below and above 32 weeks exhibited vitamin D values of 10.97±6.31 ng/ml and 18.05±11.64 ng/ml, respectively. The difference in vitamin D levels between boys (12.59±8.40 ng/ml) and girls (16.05±11.45 ng/ml) was found to be significant (P=0.009). Moderate and severe vitamin D deficiency was more common at earlier pregnancy ages (P=0.001).

CONCLUSION

Vitamin D deficiency is more common and severe in preterm infants and their mothers. Controlling vitamin D levels during pregnancy, especially in women at risk of preterm labor and preterm infants, may help reduce prematurity problems.

Association Between Vitamin D Level and Neonatal Respiratory Distress Syndrome: A Systematic Review and Meta-Analysis

BACKGROUND

In recent years, vitamin D in the occurrence of lung diseases has gradually become a hot topic. Although the role of vitamin D in normal lung development has been confirmed, the correlation between vitamin D level and neonatal respiratory distress syndrome (NRDS) is not clear.

OBJECTIVE

To evaluate the association between vitamin D level and NRDS.

METHODS

We performed a comprehensive search of the following electronic databases: PubMed, Embase, Cochrane Library, Web of Science, and China National Knowledge Infrastructure (CNKI). Literature screening and quality assessment were performed according to inclusion and exclusion criteria. The Newcastle-Ottawa Scale was used to assess the methodological components of each study, and Stata 15.1 software to perform the Meta-analysis.

RESULTS

A total of nine case-control studies were included, with 653 infants with NRDS and 501 infants without NRDS. The Meta-analysis showed no heterogeneity across all studies(I²=0.0%, P=0.583). The fixed-effect model showed that 25 hydroxy vitamin D level of children in the NRDS group was significantly lower than that of the non-NRDS group(SMD = -0.51, 95%CI: -0.63 to -0.39, p ≤ 0.05).

CONCLUSION

This systematic review and meta-analysis study suggests that vitamin D deficiency is very likely to be a high-risk factor of NRDS, and reasonable vitamin D supplementation during pregnancy and after birth is of great significance.