Association Vitamin D2 and PFAS among pregnant women from NHANES 2017-2018: A case Control Analysis

Abstract Introduction: This study uses data from the 2017-2018 NHANES survey to evaluate how exposure to perfluoroalkyl substances (PFAS) affects vitamin D2 levels in pregnant women. PFAS are widely known for their environmental persistence and potential health risks, particularly during pregnancy, as they affect important biological functions such as the metabolism of vitamin D2, which is essential for bone health and immune function. Methods: The study focused on pregnant women from the NHANES 2017-2018 cohort, using “comment code LBDVD2LC – 25OHD2” to classify vitamin D2 levels and different PFAS as exposure variables. Data analysis was carried out with R to address the complicated design of the NHANES survey. To explore associations, weighted descriptive statistics, bivariate analyzes and logistic regression were used. Results: The analysis found that most participants had vitamin D2 levels below the detection limit. PFAS exposure and reduced vitamin D2 levels were remarkably correlated. A significant association was found between increased exposure to PFAS and decreased vitamin D2 levels (p values <0.001), indicating that exposed pregnant women have low vitamin D2 levels. Conclusion: This study highlights the negative effects of PFAS exposure on vitamin D2 levels in pregnant women, helping to understand PFAS as an important risk factor during pregnancy. The goal of future studies should be to clarify specific biochemical interactions and suggest feasible public health plans to reduce this exposure.