What you need to know

Research suggests that certain dietary supplement ingredients might improve immune response and reduce symptoms of some respiratory illnesses, like the common cold and flu. Popular supplement ingredients that are thought to support immune health include vitamin C, vitamin D, zinc, elderberry, echinacea, and probiotics. During the COVID-19 pandemic, sales of these supplements increased despite the lack of reliable evidence that they are effective at preventing SARS-CoV-2 infection or reducing COVID-19 disease severity. And by law, dietary supplements are not allowed to be marketed to treat, prevent, or cure any disease; only drugs can legally make such claims.

To bridge this knowledge gap, scientists have researched whether these supplements are safe and effective ways to boost the immune system against COVID-19.