The possible impact of COVID-19 pandemic on serum vitamin D levels on newborns in Greece

Abstract

Background: Very few studies have evaluated the probable role of the period of 2019 coronovirus disease (COVID-19) pandemic on neonatal 25(OH)D levels. Vitamin D status in the fetus and newborn is largely determined by the vitamin D status of the mother. A recent study in Greece witnessed an unexpected rise in maternal 25(OH)D levels in pregnancy during the COVID-19 period. Consequently, it remains unclear whether neonatal 25(OH)D levels decreased due to reduced sun exposure in the COVID-19 period or followed their unexpected maternal findings. Methods: We studied neonatal 25(OH)D levels in cord blood specimens at birth in 246 neonates of Greek mothers with stratified random sampling, from September 2019 to January 2022. We divided our samples into the pre-COVID-19 period and the post-COVID-19 period. Chi-square test was used to find an association between neonatal 25(OH)D concentrations throughout the COVID-19 period. Quantitative results of 25(OH)D vitamin levels on newborns were transformed into qualitative variables assessing lack of 25(OH)D, adequacy, deficiency and severe deficiency and thus defined in that way. All other results of 25(OH)D levels are presented as means ± standard deviations (SD) or by frequencies and percentages. Results: The results in neonates exhibited a similar pattern to that of their mothers’. The mean serum values of 25(OH)D levels of the newborns were statistically significantly higher during the COVID-19 period compared to the pre-COVID-19 period. Conclusions: Although during the COVID-19 period lower maternal and therefore neonatal 25(OH)D levels were expected, these were higher and because of these findings, we can only make assumptions. Without a doubt, further investigation is required.