Serum 25(OH) Vitamin D Levels in Pregnant Women with Coronavirus Disease 2019 (COVID-19): A Case-Control Study

The physiological changes during pregnancy may increase the risk of complications in pregnant women with coronavirus disease 2019 (COVID-19). Vitamin D is a fat-soluble secosteroid hormone and its role in immunity is appears to be of particular importance in this recent pandemic. Nevertheless, there is little research about the role of vitamin D levels regarding COVID-19 in pregnant women to date. This study aimed to establish a relationship between serum 25-hydroxyvitamin D (25(OH)D) levels in pregnant women and COVID-19. A comparative case-control study was performed with a study population of 256 pregnant women (82 pregnant women with infection and 174 women in control group). Serum 25(OH)D levels were significantly lower in pregnant women with COVID-19 infection than in those without infection. In addition, 89% of COVID-19-positive pregnant women had 25(OH)D deficiency, while in the control group the percentage was 75.30%, finding statistically significant differences (ORa = 2.68; 95% CI 1.19-6.06; = 0.01). Our results find a relationship between vitamin D deficiency in pregnant women and COVID-19 infection. This finding could be relevant for actual clinical practice. Thus, more research is needed in this field.