Vitamins for the Prevention and/or Treatment of COVID-19: An Umbrella Review

Abstract

Objective: This umbrella review synthesizes the existing literature on the role of vitamins for COVID-19 prevention and management. The objective is to elucidate potential preventive and therapeutic dimensions of these vitamins, highlight clinical applicability, and identify avenues for future research. Methods: A systematic search was conducted using PubMed and Google Scholar, with predefined key words for each vitamin combined with COVID-19-related terms. Narrative and systematic reviews were included, following Cochrane guidelines. AMSTAR scoring was used to assess systematic review quality, while SANRA guidelines were used to evaluate narrative reviews. Data extraction, synthesis, and reference overlap were conducted. Findings: Narrative reviews (n=14) revealed preclinical benefits of vitamins A, B group, C, D, and E (no research on vitamin K found) in COVID-19 management, with potential for immune modulation and anti-inflammatory responses. Of the systematic reviews (n=44), none included vitamins A or E. Some B vitamins exhibited potential, with significant associations between vitamin C supplementation and reduced COVID-19 severity. Many significant findings were also found between vitamin D deficiency and heightened COVID-19 risks, as well as promising effects of vitamin D supplementation. Conclusion: Vitamins A, B group, C, D, and E hold mechanistic rationale for combating COVID-19, as suggested by narrative reviews. In systematic reviews, vitamin D deficiency underscores its role in COVID-19 severity, while vitamin C and D supplementation show potential benefits as adjunct therapies. This umbrella review highlights the comprehensive research on the efficacy of vitamins in addressing COVID-19, with challenges that warrant further investigation.