Antioxidant and Immune-Related Implications of Minerals in COVID-19: A Possibility for Disease Prevention and Management

Abstract

Since the coronavirus disease 2019 (COVID-19) pandemic appeared, both governments and the scientific community have focused their efforts on the search for prophylactic and therapeutic alternatives in order to reduce its effects. Vaccines against SARS-CoV-2 have been approved and administered, playing a key role in the overcoming of this situation. However, they have not reached the whole world population, and several doses will be needed in the future in order to successfully protect individuals. The disease is still here, so other strategies should be explored with the aim of supporting the immune system before and during the infection. An adequate diet is certainly associated with an optimal inflammatory and oxidative stress status, as poor levels of different nutrients could be related to altered immune responses and, consequently, an augmented susceptibility to infections and severe outcomes derived from them. Minerals exert a wide range of immune-modulatory, anti-inflammatory, antimicrobial, and antioxidant activities, which may be useful for fighting this illness. Although they cannot be considered as a definitive therapeutic solution, the available evidence to date, obtained from studies on similar respiratory diseases, might reflect the rationality of deeper investigations of the use of minerals during this pandemic.

Keywords: COVID-19; SARS-CoV-2; immunity; minerals; nutrients; oxidative stress.

Figure 1

Manuscript selection flowchart.

Figure 2

Summary of zinc’s main mechanisms of action (references detailed in brackets). Through them, this trace element exerts several effects related to physical barrier enhancement [10,13,93], innate immunity [11,79,80,83,84,85,86,87], adaptive immunity [10,78,81,82], as well as other mechanisms associated with ACE2 expression [85,89], antioxidant defense [80], and direct antiviral activity [12,78,91,92]. Color description: orange (barrier enhancement), green (innate immunity), yellow (adaptive immunity), and red (other mechanisms).

Figure 3

Summary of selenium’s main mechanisms of action (references detailed in brackets). Through them, this trace element exerts several effects related to antioxidant defense [99,100], innate immunity [32,65,98,101,102,105], adaptive immunity [100,102,103], as well as other mechanisms associated with cardiovascular protection [103], and SARS-CoV-2 viral cycle disruption [33,34,109,110]. Color description: purple (antioxidant defense), green (innate immunity), yellow (adaptive immunity), and red (other mechanisms).

Figure 4

Summary of copper’s main mechanisms of action (references detailed in brackets). Through them, this trace element exerts several effects related to innate immunity [116,117,118,119,122], adaptive immunity [65,82,116,118,120,122], as well as other mechanisms associated with antioxidant defense [116,117], autophagy induction [116,117], direct antiviral activity [38,116,119,124,125], and tissue integrity maintenance [116,117]. Color description: green (innate immunity), yellow (adaptive immunity), and red (other mechanisms).

Figure 5

Summary of magnesium’s main mechanisms of action (references detailed in brackets). Through them, this mineral exerts several effects related to innate immunity [128,129,130,131], adaptive immunity [42], as well as other mechanisms associated with cardiovascular health [131,134,135], lung function [44,45,129], and vitamin-D-related mechanisms [132,133]. Color description: green (innate immunity), yellow (adaptive immunity), and red (other mechanisms).

Figure 6

Summary of iron’s beneficial mechanisms of action and detrimental effects derived from its overload or excess (references detailed in brackets). Through these mechanisms, this trace element exerts several effects related to antioxidant defense [49], innate immunity [49,138], and adaptive immunity [65,82,138]. Its potentially negative effects are associated with immune function impairment [141], availability for microbes [141], cellular toxicity in lungs [98], and hyperferritinemia/ferroptosis [55,137,144,145,146]. Color description: purple (antioxidant defense), green (innate immunity), yellow (adaptive immunity), and blue (detrimental effects).