evidence: Finally, another important characteristic of the disease is its pathophysiology. SARS-CoV-2 infection starts with the interaction of the virus with the enzyme ACE2, reducing its activity. Importantly, ACE2 has a key role in counteracting ARDS and acute lung injury. Xu et al. (157) demonstrated that calcitriol is able to upregulate ACE2 and downregulate renin and angiotensin II in the lung tissue of rats exposed to lipopolysaccharide as a model of ARDS (157). In this scenario, recent literature have suggested that vitamin D can act by targeting ACE2 down-regulation in SARS-CoV-2 infection, which could be a potential therapeutic approach to COVID-19 and induced ARDS (158–161). However, further studies must be performed to understand the impact of ACE2 modulation for COVID-19 (17, 24, 158–162).