Investigation of the Change in Vitamin D Levels with Age, Sex and Season in the Kars Province During the COVID-19 Pandemic

Year 2025, Volume: 15 Issue: 3, 293 - 300, 05.01.2026

Ayşe Kanıcı Tarhane , Erhan Kirmik

Abstract

Aim: This study aimed to determine the effect of the COVID-19 pandemic on changes in serum vitamin D levels (by age, sex, and season) of patients residing in Kars province during the pandemic and to detect whether vitamin D supplementation was needed during this period.
Materials and Methods: In this study, a retrospective evaluation of laboratory results available in the hospital automation system of the Kafkas University Health Application and Research Center was planned.
Results: The study included 14,054 laboratory results of patients admitted to the Training and Research Hospital of Kafkas University from 01.01.2020 to 31.12.2021. Of these results, 8925 (63.5%) were from women, and 5129 (36.5%) were from men. No statistically significant difference was observed in serum vitamin levels between the COVID-19 pandemic and the non-pandemic period. The 25-hydroxyvitamin D levels of women were lower than those of men during the pandemic. When assessed for seasonality, compared with summer and autumn, the patients’ 25-hydroxyvitamin D levels were significantly lower in winter and spring.
Conclusion: The fact that the vitamin D levels of the patients in our study were shown to be close to the lower reference limit (20 ng/mL) suggests that, in the event of a pandemic, individuals may develop vitamin D deficiency and need vitamin supplementation. Given the effects of vitamin D deficiency and the associated health risks, further research and increased public awareness are needed. This study is expected to provide reference data for future research and to contribute to national and international scientific literature by offering insights on how to protect public health and raise public awareness.

Keywords

age , sex , season , vitamin D; covid 19

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