The relationship between vitamin D and the severity of COVID-19

Vitamin D, which has immunomodulatory effect, can reduce risk of infections and concentrations of pro-inflammatory cytokines. The aim of this study was to investigate the relationship between the levels of vitamin D and severity of COVID-19.

A total of 204 patients with COVID-19 disease were enrolled in the study. All patients had viral pneumonia, which was confirmed with chest computer tomography. All cases were divided in two groups- mild (outpatients); and serious (inpatients)- according to their clinical and laboratory data. Serum vitamin D levels were measured by chemiluminescence method.

Vitamin D deficiency was found in 41.7 % (n = 85) of cases and insufficiency was found in 46.0 % (n = 94), while in 12.3 % (n = 25) of cases normal vitamin D levels were found. The odds of having a serious clinical outcome were increased for vitamin D insufficiency patients 5.604 times (%95 CI:0.633-49.584) and for vitamin D deficiency patients 38.095 times (%95 CI:2.965-489.50) for each standard deviation decrease in serum 25(OH)D.

Adequate levels of vitamin D could suppress inflammation and reduce the severity of COVID-19. Vitamin D supplementation may have an important role in decreasing the impact of the pandemic (Tab. 5, Fig. 2, Ref. 27).