Study Links Low Vitamin D Levels to Increased Preterm Birth Risk

The study relied on a large dataset gathered between 2016 and 2025, supported by the South Carolina Clinical & Translational Research (SCTR) Institute, which provided various resources including biostatistical support and clinical research infrastructure. Wagner emphasized the importance of SCTR's assistance in conducting the research.

While the study does not establish a direct causal link, it adds to existing evidence that improving vitamin D status in expectant mothers may enhance both maternal and fetal health outcomes. Vitamin D is essential for calcium absorption and is crucial for maintaining bone, muscle, nerve, and immune health. It also plays a role in developing hormones critical during pregnancy.

According to Wagner, vitamin D influences thousands of genes and aids in the growth of the placenta, which nourishes the fetus. Adapting the mother’s immune system to accept the fetus, which contains genetic material from both parents, is another vital role of vitamin D.

Looking beyond pregnancy, Wagner and Borsum noted that vitamin D deficiency could have long-term health implications. Insufficient levels early in life might alter gene function, potentially affecting the child’s health for years. Vitamin D deficiency is prevalent, often exacerbated by lifestyle factors limiting outdoor activity, which reduces sunlight exposure necessary for natural vitamin D production.

Certain populations are at a higher risk for deficiency, such as individuals with darker skin and those who work indoors or have limited mobility. While sunscreen is essential to prevent skin cancer, Borsum advised those with limited sun exposure to consider discussing vitamin D levels and supplementation with healthcare providers.

Wagner acknowledged the challenge of altering clinical practices regarding vitamin D due to its low profitability compared to prescription medications. She stated that promoting vitamin D's importance has become a public health issue. The next steps for researchers include educating healthcare providers and raising public awareness about vitamin D’s multifaceted role, particularly concerning pregnancy and preterm birth.

In summary, both Wagner and Borsum hope to foster greater dialogue on vitamin D, encouraging individuals planning for pregnancy to ensure adequate levels.

Publication: Anjali G. Borsum et al, Maternal vitamin D status and preterm birth: an eight-year retrospective cohort study in the Southeastern United States, Journal of Perinatology (2026). DOI: 10.1038/s41372-026-02757-z.