Correlation between vitamin D level and severity of prognostic markers in Egyptian COVID-19 patients: a cohort study.

The outbreak of coronavirus disease 2019 (COVID-19), which is caused by the highly contagious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was announced a pandemic in March 2020 by the World Health Organization. The disease can be diagnosed on the basis of clinical symptoms, polymerase chain reaction positivity, and the presence of ground-glass opacities on computed tomography (CT) scans. Recent studies have focused on the role of serum inflammatory markers that predict COVID-19, such as lymphocyte counts and C-reactive protein (CRP), homocysteine, and D-dimer levels. Vitamin D is thought to reduce the risk of viral infections through several mechanisms. Our aim was to evaluate the correlation between serum vitamin D level and inflammatory markers and severity in Egyptian patients with COVID-19 infection. Serum vitamin D level had a positive correlation with hemoglobin level and lymphocytes. As results, serum vitamin D had a negative correlation with serum ferritin, CRP, and D-dimer and was not correlated with CORAD scoring in the CT chest. In conclusion, serum vitamin D was inversely correlated with inflammatory markers (ferritin, CRP, and D-dimer) which mean that participants with symptoms of COVID-19 had a high level of inflammatory markers and a low level of vitamin D. Participants without symptoms of COVID-19 had normal inflammatory markers and normal vitamin D level.