Vitamins and mineral supplements are commonly used to prevent chronic diseases, but a new analysis found there's little evidence that they do so, Reuters reported.

People taking vitamin or mineral supplements to boost health did not demonstrate a lower risk of heart diseases or cancer, the U.S. Preventive Services Task Force (USPSTF) found.

Based on those findings, the task force - which is responsible for helping to guide doctors and health systems - issued draft recommendation that is cannot recommend for or against taking supplements to prevent those conditions.

"At this point in time the science is not sufficient for us to estimate how much benefit or harm there is from taking vitamin or multivitamin supplements to prevent cancer or heart disease," Dr. Michael LeFevre, co-vice chair of USPSTF, told Reuters.

However, in the draft statement issued, the task force singled out beta-carotene and vitamin E as ineffective.

"In general, the task force found that there is not enough evidence to determine whether you can reduce your risk of cardiovascular disease or cancer by taking single or paired nutrients or a multivitamin," Lefevre said. "However, there were two major exceptions: beta-carotene and vitamin E, both of which clearly do not help prevent these diseases."

They warned that those two drugs should not be taken to prevent heart disease or cancer.

Previously, beta-carotene was found to further increase the risk of lung cancer among people who are already at an increased risk. The Task Force has not come out with an official recommendation because of the lack of evidence regarding the roles of the supplements.

After searching online medical research databases for studies regarding the effects of multivitamins or specific vitamins and minerals taken together or alone published between January 2005 and January 2013, the researchers included data from 26 studies.

LeFevre advised medics to counsel their patients regarding the supplements they consume and educate them about the impact of these supplements on their health.

It's estimated that Americans spend about $12 billion each year on supplements.

About 600,000 people die of heart disease in the U.S. every year, according to the Centers for Disease Control and Prevention. Another 580,000 die of cancer, according to American Cancer Society.