EFFECT OF MICRONUTRIENT SUPPLEMENTS ON MORTALITY IN PATIENTS WITH CORONAVIRUS DISEASE 2019: A SYSTEMATIC REVIEW AND META-ANALYSIS

ABSTRACT

Background and aims: Micronutrient supplements such as vitamin D, vitamin C, and zinc have been used in managing viral illnesses. However, the role of these micronutrients in reducing mortality in patients with Coronavirus disease 2019 (COVID-19) remains unclear. We conducted this meta-analysis to provide a quantitative assessment of the effect of these individual micronutrients on mortality in COVID-19. Methods: We performed a comprehensive literature search using MEDLINE, Embase, and Cochrane databases through November 5th, 2021. All individual micronutrients reported by ≥3 studies and compared with standardof- care (SOC) were included. The outcome was mortality. All statistical analyses were performed using the Review Manager. Pooled risk ratios (RR) and corresponding 95% confidence intervals (CI) were calculated using the random-effects model. Results: We involving 5573 COVID-19 patients that compared three individual micronutrient supplements (vitamin C, vitamin D, and zinc) with SOC. Eight studies evaluated vitamin C in 1338 patients (530 in vitamin C and 808 in SOC). Vitamin C supplementation had no significant effect on the risk of mortality (RR 1.06, 95% CI 0.63-1.80, P=0.82, Figure 1A). Fourteen studies assessed the impact of vitamin D supplementation on mortality risk among 3497 patients (927 in vitamin D and 2570 in SOC). Vitamin D did not reduce the mortality risk in patients (RR 0.75, 95% CI 0.49-1.17, P=0.21, Figure 1B). Subgroup analysis showed that vitamin D supplementation was not associated with a mortality benefit in patients receiving vitamin D pre or post COVID-19 diagnosis (Figure 1B). Five studies, including 738 patients, compared zinc intake with SOC (447 in zinc and 291 in SOC). Zinc supplementation was not associated with a significant reduction of mortality (RR 0.79, 95% CI 0.60- 1.03, P=0.08, Figure 1C). Subgroup analyses of RCTs for all three micronutrient supplements showed consistent findings (Figure 2). Conclusions: Individual micronutrient supplementations, including vitamin C, vitamin D, and zinc, did not reduce mortality in patients with COVID-19. Further research is needed to validate our findings. (Figure Presented)