A new randomized study by the Cleveland Clinic showed that vitamin C and zinc didn't significantly reduce the duration of COVID symptoms.
In fact, researchers stopped the study early because there was no real distinction between the four groups: those who received regular care, those who received extra vitamin C, those who received extra zinc and those who received extra of both.
"Unfortunately, these two supplements failed to live up to the hype," Dr. Erin Michos of John Hopkins and Houston Methodist's Dr. Miguel Cainzos-Achirica said.
The clinical trial offered high doses of each supplement alone and in combination with one of the three groups of 214 adults recovering at home. The fourth group received standard treatment, such as rest, hydration and fever-reducing medicines, but no supplements.
Participants were asked to monitor their condition daily. They also filled out a questionnaire at the start of the experiment and every week to assess if they had been hospitalized or had side effects on supplements.
"High-dose zinc gluconate, ascorbic acid or both supplements didn't reduce SARS-CoV-2 symptoms," according to Cleveland Clinic cardiologist Dr. Milind Desai and a team from Cleveland Clinic.
An operational and safety monitoring board at the Cleveland Clinic suggested halting the study. The data on the 214 participants enrolled at the time of study completion are the final data for this study.
Vitamin C is a known antioxidant and plays a key role in strengthening the immune system. While it has not been proven to prevent disease, further research has shown that vitamin C can reduce colds by 8% in adults and 14% in children.
Zinc may improve a cell's ability to combat infection, the study said, "while there is evidence that zinc deficiency increases pro-inflammatory cytokines and decreases the production of antibodies."
More studies are ongoing to see if supplements such as vitamins C and D and zinc can inhibit COVID-19.
Scientists continue to investigate the use of vitamins and supplements. Based on this analysis, however, the use of vitamin C and zinc to shorten the duration of COVID seems to be pointless.