A Lower 25(OH)D Level in COVID-19 Patients is Associated with Increased Mortality: An Observational Study

Background: Recent studies have shown that insufficient vitamin D supply is correlated with increase in COVID-19 cases and its mortality. Potentially, it may play an important role in controlling virus proliferation. Objectives: This study aimed to evaluate the association between serum vitamin D levels and clinical findings, and mortality rate in patients with COVID-19. Methods: This cross-sectional study was conducted on 200 COVID-19 patients referred or admitted to Loghman-e-Hakim Hospital of Tehran, Iran, from February to June 2020. After patient selection, demographic information of all patients was recorded. Eventually, the relationship between basic demographic and clinical findings with vitamin D levels in all patients was evaluated. Results: The mean Vit-D levels in intubated and non-intubated patients were 22.95 ± 22.23 ng/mL and 21.64 ± 29.20 ng/mL, respectively (P = 0.018). In most of the outpatients (46.7%), Vit-D levels were between 21 - 30 ng/mL, and 47.6% of admitted patients had Vit-D ≤ 20 ng/mL. The mean Vit-D level in survived patients was significantly higher than patients who died (28.2 ± 21.18 ng/mL vs. 19.91 ± 14.18 ng/mL, respectively; P = 0.021). While 34.2% (55 cases) of survived patients had Vit-D level ≥ 31 ng/mL, about 70% of death cases had Vit-D ≤ 20 ng/mL (P < 0.001). Conclusions: According to our results, vitamin D supplementation could be beneficial in COVID-19 patients. However, further comprehensive clinical trials are needed to confirm these findings.