Effect of PM2.5 exposure on Vitamin D status among pregnant women: A distributed lag analysis

Abstract

BackgroundSerum vitamin D levels are associated with exposure to air pollution, however, the lagged effect of exposure to air pollution remains unknown in pregnant women. MethodsPregnant women who delivered at a maternity center in Shanghai, China, from 2015 to 2019 were included in the present study. The concentration of particulate matter 2.5 (PM2.5) before 25-Hydroxyvitamin D [25(OH)D] detection was estimated using the satellite-based grid models. The distributed lag non-linear models were performed to examine the lagged association between weekly-specific PM2.5 exposure and vitamin D deficiency (VDD) or serum 25(OH)D levels. ResultsAmong the 58,025 pregnant women included in the study (mean age at conception, 30.77 ± 3.75 years; mean prepregnancy BMI, 21.09 ± 2.55 kg/m2), 61.32% were diagnosed with VDD. Weekly-specific PM2.5 exposure at weeks 1–10 before the detection of 25(OH)D was significantly associated with an increased incidence of VDD (p < 0.05). For every 10 μg/m3 increase in PM2.5 exposure, the serum 25(OH)D level decreased by 1.346 nmol/L (95%CI: 1.183–1.508 nmol/L). The association between average PM2.5 exposure and VDD at 1–10 weeks was more significant in weather conditions with low mean sunshine hours (OR: 1.246, 95%CI: 1.221–1.271). ConclusionOur study provided suggestive evidence that PM2.5 exposure at 1–10 weeks before the 25(OH)D detection may decrease the circulating 25(OH)D levels in pregnant women and increase VDD risk in pregnant women. More attention should be paid to the long-term impact of PM2.5, in particular, during weather conditions with a relatively short duration of sunshine.