Zinc and vitamin C supplements may help boost the immune system, but they offer little, if any, benefit as a treatment for coronavirus disease 2019 (Covid-19), according to a study published Friday by JAMA Network Open.

On the other hand, it was found out that Vitamin D can help increase the chances of survival of Covid-19 patients.

The study was “terminated” after 10 days of treatment with either zinc, vitamin C or both because they did not produce improvement in non-hospitalized patients infected with Covid-19, the researchers said.

“High-dose zinc or vitamin C or [both in] combination do not reduce duration of illness in outpatients affected by Covid-19 as compared to standard of care,” study co-author Dr. Milind Desai said.

As the trial did not reach its “primary endpoint,” which was proof of the beneficial effects of zinc or vitamin C, [it] was terminated early,” said Desai, a professor of cardiovascular medicine at the Cleveland Clinic in Ohio.

Several studies have explored the benefits of immune system-boosting supplements in treatmenting Covid-19, either alone or in combination with drug therapy.

One supplement, vitamin D, is known to be important for immune health, and research has suggested that low levels may raise Covid-19 infection risk – and treating infected patients with the vitamin has been shown to improve odds for survival.

Based on the findings of Desai and his colleagues, however, the same does not appear to hold true for zinc and vitamin C.

For this study, Cleveland Clinic researchers treated 214 patients with confirmed Covid-19 infection with either 50 milligrams per day of zinc, 8,000 mg. per day of vitamin C, both or neither for 10 days.

Patients who received usual care without the supplements achieved a 50-percent reduction in virus symptoms after about seven days, the data showed.

While those given vitamin C, zinc or both also saw a 50-percent reduction in symptoms after about six days, the researchers said this difference was not significant enough to continue use of either for Covid-19 treatment.