MATERNAL VITAMIN D SUPPLEMENTATION AND ITS ASSOCIATION WITH PREGNANCY OUTCOMES, NEONATAL PHYSIOLOGICAL ADAPTATION, AND EARLY INFANT HEALTH: AN ANALYTICAL CROSS-SECTIONAL STUDY”

Abstract

Background: Maternal vitamin D deficiency remains a prevalent global health concern linked to adverse maternal, fetal, and neonatal health outcomes. Despite growing awareness, variations in regional clinical practices and adherence to maternal supplementation continue to impact developmental trajectories. This study evaluated the association between maternal vitamin D supplementation during pregnancy and key metrics of maternal pregnancy outcomes, neonatal physiological adaptation, and early infant health. Methods: An analytical cross-sectional study was conducted among mothers and their full-term singleton infants (N = 350) presenting at tertiary care facilities over a 06 months period. Maternal vitamin D status and supplementation history (dose, timing, and consistency) were documented alongside maternal serum 25 hydroxyvitamin D [25(OH)D] levels measured at delivery. Primary outcomes included maternal gestational complications (gestational diabetes, preeclampsia), neonatal physiological adaptation at birth (APGAR scores, umbilical cord blood gas analysis, neonatal serum calcium), and early infant health outcomes (birth weight, incidence of early-onset neonatal infections, and 6-week infant growth indices). Multivariate logistic regression and linear regression models were utilized to adjust for confounding variables including maternal age, baseline BMI, socioeconomic status, and gestational age at birth. Results: Mothers who received consistent vitamin D supplementation (600 IU/day or more) demonstrated significantly higher mean delivery 25(OH)D levels compared to non-supplemented mothers (28.4 ± 6.2 ng/mL vs. 14.1 ± 4.8 ng/mL, p < 0.001). Maternal vitamin D supplementation was associated with a reduced risk of preeclampsia (AOR = 0.42, 95% CI: 0.21–0.84) and lower rates of low birth weight (AOR = 0.38, 95% CI: 0.19–0.76). Neonates born to supplemented mothers exhibited superior physiological adaptation, characterized by higher 5-minute APGAR scores (p = 0.008), reduced rates of neonatal hypocalcemia (3.2% vs. 14.8%, p < 0.001), and higher mean cord serum 25(OH)D levels. At the 6-week follow-up, infants of supplemented mothers showed improved weight-for-age z-scores and a lower incidence of acute respiratory tract infections (AOR = 0.51, 95% CI: 0.29–0.90). Conclusion: Adequate maternal vitamin D supplementation during pregnancy is strongly associated with a reduced incidence of maternal gestational complications, improved neonatal physiological transition at birth, and favorable early infant health and growth metrics. These findings support routine monitoring and targeted maternal supplementation protocols to optimize perinatal and early infant health outcomes.