Preterm birth 2.5 times more likely if low Vitamin D
Relationship of Maternal 25-Hydroxyvitamin D₃ Deficiency With the Occurrence of Preterm Labor
Cureus 2026 May 9;18(5):e108559. doi: 10.7759/cureus.108559
Rubeena Badar 1, Muntiha Sarosh 2, Tehmina Zafar 1, Rupak Shrestha 3, Faiza Ghafoor 4, Anam Bashir 5, Tayyaba Majeed 1
Preterm labor remains a major contributor to neonatal morbidity and mortality, particularly in regions where nutritional deficiencies are common.
Objective: This study assessed the relationship between maternal vitamin D₃ deficiency and the occurrence of preterm labor. Methods: This cross-sectional analytical study was conducted at Central Park Teaching Hospital, Lahore, from December 2023 to December 2024, and included 316 pregnant women. Participants were categorized into a preterm labor group (n = 148) and a term delivery group (n = 168). Serum 25-OH-D₃ levels were measured using a chemiluminescent immunoassay and classified as deficient, insufficient, or sufficient.
Results: Vitamin D₃ deficiency was highly prevalent (67.1%) and significantly more common in women with preterm labor (80.4%) than those with term deliveries (55.4%) (p < 0.001). Mean serum vitamin D₃ levels were markedly lower in the preterm group (15.8 ± 5.9 ng/mL) compared with the term group (22.4 ± 7.1 ng/mL) (p < 0.001). Logistic regression demonstrated that vitamin D₃ deficiency remained an independent predictor of preterm labor (adjusted OR = 2.51, 95% CI: 1.62-3.89). Additional significant factors included hemoglobin <10 g/dL (aOR = 1.68), sun exposure <30 minutes/day (aOR = 1.74), antenatal visits <4 (aOR = 1.82), and previous preterm birth (aOR = 1.91).
Conclusions: Maternal vitamin D₃ deficiency is strongly associated with preterm labor and remains a significant independent predictor even after adjusting for clinical and demographic factors. Given its high prevalence and modifiable nature, routine screening and targeted vitamin D₃ supplementation may help reduce the burden of preterm birth.
Related in Vitamin D Life
- Low Vitamin D while pregnant increased risks: preterm birth 2.4X, development delay 4.4X
- While in labor, preterm birth delayed 6 days by Vitamin D (single dose of 50,000 IU) - RCT
- 3X fewer preterm deliveries if take 2,000 IU of Vitamin D daily (small study, 9% refused)
- Preterm birth rate increased in US but decreased in Finland (high Vitamin D)
- Preterm birth rates increased in 15 European countries
- Preterm births reduced by Vitamin D - many studies
- Preterm birth 8X more likely if poor Vitamin D Receptor
- Preterm Births - promising preventions – anti-oxidants, Vitamin D, Omega-3, Zinc, etc.
- [FDA petitioned to acknowledge that vitamin D cuts preterm birth rate in half] (2018)(/pages/fda-petitioned-to-acknowledge-that-vitamin-d-cuts-preterm-birth-rate-in-half/)
- Vitamin D intervention reduces preterm births and low birth weight by 60 percent – Cochrane Reviews
- Preterm birth cost for employers approximately 50,000 dollars
- Preterm labor 20 times more likely if low vitamin D, etc. (India)
- The more preterm the birth, the lower the vitamin D level (both mothers and infants)
- Osteopenia in preterm infants