Background: During the 2019 coronavirus disease (COVID-19) pandemic, lockdown was implemented, which likely reduced maternal 25(OH)D levels in pregnancy due to reduced sun exposure from social distancing measures and confinement at home. At the same time, however, due to the lockdown and the ban on the free movement of vehicles, the emissions of many atmospheric pollutants also decreased. We know that air pollution and low ground level ultraviolet B radiation (UVB; 290-315) can deteriorate the body's vitamin D status in healthy women living in a polluted area, which plays a significant independent role in vitamin D deficiency (VDD) and, hence, residence can be one of the main reasons of vitamin D status in women. The reduction in air pollution likely produced positive changes in maternal 25(OH)D levels. Methods: We studied serum 25(OH)D in mothers who came for delivery, with stratified random sampling, from 27 September 2019 to April 14, 2021. We divided our sample into the pre-COVID period and the post-COVID period. Quantitative results of 25(OH)D vitamin levels on the mother were converted to qualitative variables assessing lack of 25(OH)D, adequacy, deficiency, and severe deficiency of maternal concentrations and, thus, defined. The results of 25(OH)D are presented as means ± standard deviations or by frequencies and percentages. The Chi-square test was used to find an association between maternal 25(OH)D concentrations within the COVID-19 period. Results: The results of our study showed a paradox. The mean values of 25(OH)D levels of the mothers were statistically significantly higher during the COVID-19 period compared to the pre-COVID-19 period. Conclusions: In conclusion, pregnant women should be encouraged to lead a healthier lifestyle, avoid being outside during rush hours, take nature walks, not smoke, exercise, take leisurely morning walks in the sun, and taking take their vitamin D supplements, which are recommended according to the gestational age, imitating all that they did during the pandemic, in order to avoid VDD. [ABSTRACT FROM AUTHOR]