Can vitamin C and zinc help you fight off Covid-19?No, not even at high doses, according to the first randomized clinical trial to test the two supplements under medical supervision.

Despite the popular use of vitamin C and zinc to fight off or lessen the severity of viral colds and flu, the new study, published Friday in JAMA Network Open, found the two supplements were of no benefit to people isolating at home with Covid-19.In fact, the findings were so unimpressive that the study was stopped early.

"Unfortunately, these 2 supplements failed to live up to their hype," wrote Dr. Erin Michos of John Hopkins and Houston Methodist's Dr. Miguel Cainzos-Achirica, in an accompanying editorial.

The clinical trial gave high doses of each supplement alone and in combination to one of three groups of 214 adults who were recovering at home. A fourth group got standard care, such as rest, hydration and fever-reducing medications, but no supplements.
"High-dose zinc gluconate (zinc), ascorbic acid (vitamin C), or both supplements did not reduce SARS-CoV-2 symptoms," according to Cleveland Clinic cardiologist Dr. Milind Desai and a team from Cleveland Clinic.

The high doses, however, did cause some unpleasant side effects for patients taking the supplements.

"More adverse effects (nausea, diarrhea, and stomach cramps) were reported in the supplement groups than in the usual care group," wrote Michos, an associate professor of medicine at Johns Hopkins University School of Medicine, and Cainzos-Achirica, an assistant professor of preventive cardiology at Houston Methodist.
Popular supplements