The novel coronavirus disease of 2019, also known as COVID-19 is caused by a severe respiratory syndrome (SARS-CoV-2 virus) in humans. There are limited research findings regarding the antiviral effects of zinc. Initially, it was shown that zinc lozenges that coat the oral cavity with zinc were effective with short-term duration against rhinovirus infections at doses greater than 75 mg zinc daily. It has also been proposed that zinc can restrict influenza virus infections. The antiviral effects of zinc against rhinoviruses and influenza are assumed to improve the immune cell function.

Also, it has been proposed that zinc can prevent coronavirus replication by the inhibition of RNA synthesis. It is obvious that there is an urgent need to further examine the antiviral mechanisms of zinc, predominantly related to coronaviruses. SARS-CoV-2, influenza and rhinoviruses use different cellular receptors, however the presence of angiotensin-converting enzyme 2 (ACE2) on the epithelium of the oral cavity and upper airway system provides an excellent rationale for oral zinc treatment.

Double-blind, placebo-controlled studies are necessary to prove the efficacy of zinc supplements against SARS-CoV-2. Because of their safety, availability and possible benefits, they should be strongly considered for immediate studies by health investigators to recognize a promising tool that can act against COVID-19. In these dangerous circumstances of pandemic, there is possible benefit in taking oral zinc supplements for those who are at risk of developing COVID-19. Social distancing and careful hand hygiene is of the highest importance in controlling the spread of COVID-19 and should be the primary strategy against the coronavirus pandemic. In conclusion, examining oral zinc supplementation for the prevention of COVID-19 should start immediately.

Source: Am J Ophthalmol. 2020; S0002-9394(20)30213-0. doi:10.1016/j.ajo.2020.04.028