Endocrine Abstracts

Background: The coronavirus disease 2019 (COVID-19) pandemic led to changes in lifestyle, which could influence vitamin D status on a population level. The purpose of our study was to compare 25-hydroxyvitamin D (25[OH]D) levels in patients hospitalized because of severe COVID-19 during two waves of the pandemic (2020/21 vs. 2021/22).

Materials and methods: We analyzed 101 patients (61 males/ 40 females) hospitalized in the internal medicine department of University Hospital Bratislava during the third wave of COVID-19 pandemic (Group 2). The patients from the third wave of the pandemic were compared to 101 (61 males/ 40 females) sex and age-matched subjects from the second wave of the COVID-19 pandemic (Group 1). Patients were first matched for sex, then for age +/- 1 year. If several options were available for the match, patients with the closest value of BMI were chosen. Patients from both waves were hospitalized during the winter season: the second wave was considered from 1 December 2020 to 28 February 2021, and the third wave from 1 December 2021 to 28 February 2022. Both sexes were analyzed together, as well as separately. Analyses were also performed according to the age of the participants. Younger age was defined as <65 years, and older age was defined as < 65 years. Serum 25(OH)D concentration > 30 ng/ml was considered vitamin D sufficiency and concentration <20 ng/ml deficiency.

Results: The mean concentration of 25(OH)D on admission during the second wave of the pandemic (Group 1) was 17.76 ng/ml, which increased to 25.21 ng/ml during the third wave (Group 2) (P<0.0001). On admission, 82% of patients from Group 1 were 25(OH)D deficient, and 10% were 25(OH)D sufficient. In Group 2, 54% of patients were 25(OH)D deficient, and 34% of patients were 25(OH)D sufficient (P<0.0001). The proportion of patients with a history of vitamin D supplementation increased from 18% to 44% (P<0.0001). The most significant absolute change of 25(OH)D concentration between waves was observed in younger males (10,70 ng/ml, P=0.002), and the smallest absolute change of 25(OH)D concentration was observed in younger females (2,49 ng/ml, P=0.676). Serum 25(OH)D concentration higher by one ng/ml was associated with a ~ 7% increase in the chance of survival for given age and sex category.

Conclusions: The prevalence of inadequate vitamin D status in hospitalized patients with COVID-19 in Slovakia decreased significantly due to a higher rate of vitamin D supplementation during the COVID-19 pandemic.