Table 1.

The possible effects of some micronutrients on common symptoms of COVID-19 and obesity.

Micronutrients	Key Mechanism of Action	Outcomes	References
Vitamin A	• Inhibition of M1 macrophage • Downregulation of IFN-γ • Promotion of Treg via inhibiting Th17 shifting • Inhibition of ACE2 by isotretinoin • Epithelial cell repairing properties	• Inflammatory status ↓ • Probably insulin resistance ↓ • Probably viral replication ↓ • Lung damage prevention	(51–55)
Vitamin C	• Protection of the respiratory system • Promotion of antioxidation and anti-inflammation properties • ROS scavenging activity • Inhibition of NF-κβ pathway	• Inflammatory status ↓ • Immunity ↑	(56)
Vitamin D	• Reduction of the risk of contracting respiratory infections • Regulation of Th1/Th2 balance	Immunity ↑	(57)
Vitamin E	• ROS scavenging activity • Inhibition of acute neutrophil inflammation in lung	• Inflammatory status ↓ • Lung damage prevention	(58, 59)
B vitamins	• Protection the respiratory system • Reduction of the risks of infection and re-infection • Reduction of inflammatory cytokine production • Regulation of the CD4/CD8 ratio and natural killer cell activity by vitamin B12 • Inhibition of ACE2 by folic acid • Prevention of hyperhomocysteinemia by folic acid, B6, and B12	• Inflammatory status↓ • Lung damage prevention • Immunity ↑ • Probably insulin resistance ↓ • Probably viral replication ↓ • Prevents thromboembolism	(60–64)
Selenium	• Antioxidative and anti-inflammatory properties in high-risk adults • Regulation of M1/M2 macrophage • Cofactor for glutathione peroxidase • Oxidizing capacity • Anticoagulant	• Inflammatory status ↓ • Antiviral activity ↑ • Prevents thromboembolism	(65, 66)
Zinc	• Antioxidative and anti-inflammatory properties in high-risk adults • Reduction of inflammatory cytokine production • Regulation of Th1/Th2 balance • Inhibition of ACE2 • Exert antiviral effect	• Inflammatory status↓ • Immunity ↑ • Probably insulin resistance ↓ • Probably viral replication ↓	(67–73)
Copper	• Regulation of Th1/Th2 balance • Reduction of inflammatory cytokine production • Oxidizing activity	• Inflammatory status↓ • Antiviral activity ↑	(74–76)
Magnesium	• Reduction of inflammatory cytokine production • Regulation of M1/M2 macrophage • Inhibits PARP	• Inflammatory status↓ • Prevents thromboembolism • Lung damage prevention	(77, 78)