Abstract

Background: The coronavirus disease-2019 (COVID-19) has become a worldwide health issue with widespread hospitalization and dependence on the intensive care unit (ICU). Vitamin D has a key role in modulating immune cells and modulating the inflammatory responses. This study aimed to investigate the association of vitamin D supplementation with inflammatory, biochemical, and mortality indices in critically ill patients with COVID-19. Methods: This case-control study was conducted on critically ill COVID-19 patients hospitalized in the ICU including the survived >30 day patients as the case group and dead patients as the control group. The status of vitamin D supplementation and inflammatory and biochemical indices of the patients were retrieved from the medical records. Logistic regression method was used to assess the association between 30 days survival and vitamin D supplement intake. Results: Compared to the group of COVID-19 patients who died in <30 day, the survived patients had a lower eosinophile level (2.2 ± 0.5 vs. 6 ± 0.0, p <.001) and higher vitamin D supplementation duration (9 ± 4.4 vs. 3.3 ± 1.9 day, p =.001). Vitamin D supplementation had a positive association with survival in COVID-19 patients (OR: 1.98, 95 CI: 1.15−3.40, p <.05). The association remained significant after adjustments fot age, sex, underlying diseases, and smoking. Conclusion: Vitamin D supplementation in critically ill patients with COVID-19 has the potential to increase survivability within the first 30 days of hospitalization. © 2023 The Authors. Immunity, Inflammation and Disease published by John Wiley & Sons Ltd.