Abstract
Background The coronavirus disease 2019 (COVID-19) is a respiratory virus, the spread of which has caused a global pandemic with catastrophic consequences. The current study aimed to investigate the association between vitamin D deficiency and the clinical presentation of COVID-19. Patients and methods The current study included 166 COVID-19 patients recruited from Prince Mohammad Bin Abdulaziz Hospital in Riyadh, Saudi Arabia. The study was conducted from October 2020 to January 2021. Patients were diagnosed by positive polymerase chain reaction (PCR) results. History and clinical data were collected for all subjects. In addition, laboratory analysis was done to estimate blood levels of 25 hydroxyvitamin D (25(OH)D), C-reactive protein (CRP), ferritin, parathyroid hormone (PTH), alanine aminotransferase (ALT), D-dimer, calcium, and relative lymphocytic count. COVID-19 patients were divided into three subgroups according to their vitamin D status. Patients were considered sufficient when their vitamin D level was above 30 ng/mL. Patients with vitamin D levels below 20 ng/mL were considered deficient. Patients with vitamin D levels ranging from 20 ng/mL to 30 ng/mL were considered insufficient. Results Our results showed that 81 patients (49%) were deficient in vitamin D, and 48 patients (29%) were insufficient in vitamin D. Only 37 patients (22%) had normal vitamin D levels. Moreover, a significant difference was found regarding the inflammatory markers of COVID-19 severity. Also, vitamin D levels were inversely correlated with the markers used for monitoring the condition of COVID-19 patients: ferritin, CRP, and D-dimer. Conclusion Our results showed that vitamin D deficiency was associated with increased levels of inflammatory markers of COVID-19 infection.