Research published in JAMA on Nov. 27 showed that patients with HIV who were not taking anti-retroviral drugs were more likely to delay the progression of their disease to AIDS if they took the supplements, CBS News reports.  

The two-year study focused on about 900 HIV-infected patients in Botswana who had not been taking any medication. The patients were either given a multivitamin; a selenium supplement; both the multivitamin and selenium; or a placebo.

The results for those that took the multivitamin or selenium only were about the same as the group that took the placebo. But, those that took both the multivitamin and selenium were 50 percent less likely to have disease progress compared to those who took the placebo. 

More than 1.1 million people in the U.S. are currently living with HIV, according to government estimates.

Dr. Jared Baeten, an associate professor of global health at the University of Washington in Seattle who was not involved in the study, said to HealthDay. "Only the combination of vitamins plus selenium was effective. For U.S. patients, this latter point is relevant, as there's a huge variety of supplements available. I would suggest talking with a doctor before taking any supplements."