Vitamins and dietary supplements are a waste of money for most people

It is unclear whether dietary supplements can help prevent cancer or cardiovascular disease in most adults, according to updated U.S. recommendations by Prevention Services Working Group. And some types of supplements are associated with cancer risk.

For example, more than half of American adults take supplements. Many people think that it is a healthy way to fill a gap in their diet but the new guidelines contradict these general concepts. The working group consists of 16 independent health professionals and provides advice on preventive health measures, such as screenings, counseling and medicines.

84 case studies were analysed on the use of additives to make the most recent recommendations, of which 54 have been published since the group last published additional recommendations in 2014. "We have not found enough evidence to recommend or prohibit the use of many combinations of vitamins and minerals, including multivitamins, to prevent cardiovascular disease and cancer," said Michael Barry, the group's vice president.

In particular, the working group made recommendations for vitamin E and beta-carotene supplementation. Vitamin E supplements have no beneficial effects in preventing premature death, cardiovascular disease or cancer. There is also evidence that beta-carotene, a pigment that transforms vitamin A in the body, increases the risk of lung cancer in people who smoke or are exposed to asbestos, Barry said.

The working group explained that these new recommendations do not apply to people with vitamin and mineral deficiencies or those who have recently become pregnant or may become pregnant. "In this case, we have separate tips on how to use folic acid to prevent neural tube defects in developing children," says Barry. For many people, dietary supplements can be a waste of time and money, according to researchers at Northwestern University in Illinois.

"Unfortunately, we know that vitamins and supplements are not good for healthy Americans," said lead author Jenny Jia. "Many people think that vitamins are completely harmless, but we have found that in some cases, vitamins can be harmful."

Taking supplements can give people a false sense of security, says Barry. As a result, they can give up other effective measures to prevent cancer and cardiovascular disease, such as a healthy diet rich in fruits and vegetables, exercise and adherence to cancer screening recommendations.