Figure 1. Flow chart of study selection.

Figure 2. Association of plasma vitamin D level with mortality in patients with COVID-19.

Figure 3. Effect of vitamin D supplementation on the risk of death in patients with COVID-19.

Figure 4. Association of plasma vitamin D level with need for hospitalization in patients with COVID-19.

Figure 5. Association of plasma vitamin D level with ICU admission in patients with COVID-19.

Figure 6. Association of plasma vitamin D level with ventilation requirement in patients with COVID-19.

Figure 7. Association of plasma vitamin D level with COVID-19 severity (Death, ICU and need for ventilation).