Effectiveness of nutritional supplements (vitamins, minerals, omega-3, and probiotics) in preventing and treating COVID-19 and viral respiratory infections

Background

Viral respiratory infections (VRIs) continue to be among the most common illnesses and are known to be one of the main reasons of medical consultations worldwide.

COVID-19 remains a major public concern and a threat to global health. The current focus lies on the pivotal role of the human host's immunologic response in combating viral threats.

This critical review aims to examine the current evidence on the potential benefit of nutritional supplements in the prevention and treatment of COVID-19 and viral respiratory infections (VRIs).

Methods

The study was performed in the Google-Scholar and PubMed databases with a main emphasis on publications between January 2000 and September 2023. Consequently, a total of 202 articles were included in this literature review, distributed as follows: 62 meta-analyses and systematic reviews, 20 randomized clinical trials, 11 clinical trials, 28 observational cohorts and 81 others. Of these, 44 % were published between 2020 and 2023.

Results

The research indicates that Vitamin C may have a mitigating effect on VRIs, whereas a deficiency in Vitamin D might heighten susceptibility to COVID-19. Understanding the roles of Vitamins A, B, and E is hampered by limited data availability. Zinc supplementation and probiotics emerge as potential preventive measures for both COVID-19 and VRIs, with selenium and magnesium demonstrating promising results in treating VRIs. The recommendation for omega-3 fatty acid supplementation for COVID-19 treatment awaits further evidence.

Conclusion

Currently, there is insufficient clinical evidence to definitively establish the efficacy of vitamin, mineral, probiotic and/or omega-3 supplementation for combating COVID-19 and VRIs.