This study, conducted by Turkish researchers, investigated the effect of vitamin D levels on COVID-19 severity and mortality in 149 COVID-19 patients. Results showed that patients with critical complaints had significantly lower vitamin D levels than patients with moderate COVID-19 complaints. Vitamin D insufficiency was measured in 93.1% of the patients with critical complaints. In conclusion, this study showed a direct association between vitamin D levels and complaints and mortality rate in COVID-19 patients. More details can be found in the study.
Karahan et al.