Vitamin D supplementation and Covid‐19 outcomes: A systematic review, meta‐analysis and meta‐regression

Hariyanto, Timotius Ivan; Intan, Denny; Hananto, Joshua Edward; Harapan, Harapan; Kurniawan, Andree

Vitamin D has many protective properties and potential role against acute lung injury. Low serum vitamin D is associated with high risk of pneumonia and development of acute respiratory distress syndrome. This study sought to analyse the efficacy of vitamin D in improving the outcomes of coronavirus disease 2019 (Covid‐19) patients. Using specific keywords, we comprehensively searched the potential articles on PubMed, Europe PMC and ClinicalTrials.gov database until 8th May 2021. All published studies on Covid‐19 and vitamin D were retrieved. Statistical analysis was conducted using Review Manager 5.4 software. A total of 11 studies with 22,265 Covid‐19 patients were included in the meta‐analysis. Our data suggested that vitamin D supplementation was associated with reduction in intensive care unit admission rate (OR 0.27; 95% CI: 0.09–0.76, p = 0.010, I (2) = 70%, random‐effect modelling); reduction of the need for mechanical ventilation (OR 0.34; 95% CI: 0.16–0.72, p = 0.005, I (2) = 61%, random‐effect modelling) and reduction of mortality from Covid‐19 (OR 0.37; 95% CI: 0.21–0.66, p < 0.001, I (2) = 50%, random‐effect modelling). Further analysis showed that the associations were influenced by age (p = 0.020). Our study suggests that vitamin D supplementation may offer beneficial effects on Covid‐19 outcomes. However, more randomized clinical trials are required to confirm this conclusion.