ion to a healthy diet and fall within recommended upper safety limits set by scientific expert bodies. Therefore, implementing an optimal nutrition, with micronutrients and omega-3 fatty acids supplementation, might be a cost-effective, underestimated strategy to help reduce the burden of infectious diseases worldwide, including coronavirus disease 2019 (COVID-19).

1. Introduction
The immune system defends the body against infectious agents and other internal and external insults. The immune defense system comprises a combination of anatomic physical barriers, including the skin, mucous membranes, mucous blanket, and ciliated epithelia