Vitamin D deficiency and preterm birth: results of a clinical study

Vitamin D plays a crucial role in maintaining reproductive health and ensuring a normal course of pregnancy. Its deficiency is associated with an increased risk of preterm birth, gestational diabetes, preeclampsia, and low birth weight in newborns. Aim - to assess 25(OH)D levels in pregnant women and determine their association with gestational age at birth (term or preterm). A comparative analysis of 25(OH)D concentrations was conducted between mothers who delivered at term and those who experienced preterm birth. Materials and methods. The study was conducted from October 2023 to September 2024. A total of 116 pregnant women participated, divided into two groups: the main group (64 women) with preterm birth (<37 weeks) and the control group (52 women) with term birth (≥37 weeks). Serum 25(OH)D levels were measured using enzyme-linked immunosorbent assay. Results. The mean 25(OH)D level in women of the main group (14.9±7.3 ng/mL) was significantly lower than in the control group (23.6±8.5 ng/mL). The proportion of women with severe 25(OH)D deficiency (<10 ng/mL) was notably higher in the main group (34.4% vs. 23.1%). Newborns from preterm births also had lower 25(OH)D levels (15.8±8.1 ng/mL) compared to those in the control group (20.3±9.2 ng/mL). Women who experienced preterm birth had a lower BMI, lower body weight, and were more likely to require cesarean delivery (65.6% vs. 30.8%). This may be linked to vitamin D deficiency, which affects metabolism, placental function, and inflammatory processes. Conclusions. 25(OH)D deficiency is a significant risk factor for preterm birth. Women with lower levels of this metabolite were more likely to deliver preterm, and their newborns had lower birth weight and reduced 25(OH)D concentrations. The findings support the need for monitoring and correcting vitamin D levels during pregnancy to reduce the risk of obstetric complications. The study was conducted in accordance with the principles of the Declaration of Helsinki. The study protocol was approved by the local ethics committee of the participating institution. Informed consent was obtained from all participants. The authors declare no conflict of interest.