As the vitamin industry continues to boom as it promises that supplements can prevent various health issues, more and more studies are exposing these claims.
Now, a new study has focused on getting to the bottom of a popular myth – whether multivitamins can prevent heart attack, strokes and other cardiovascular death.
The study, by researchers at the University of Alabama at Birmingham, analysed data on 2000 people over 12 years and found that supplements made no impact on heart health.
Lead author, Joonseok Kim, said supplements could be detrimental as people who took multivitamins felt they were improving their health, so made little other effort.
"It is immensely difficult to convince the public that multivitamin and mineral supplements don't prevent cardiovascular diseases – especially when there is a strong preconception and commercial profits at stake," Dr Kim told the Daily Mail.
"People tend to prefer a quick and easy solution, such as taking a pill, rather than the more effortful method to prevent cardiovascular disease.
"It is easy to believe that taking [multivitamin] supplements can fill the nutritional gap that people may have, and improve cardiovascular health. Despite this strong popular belief, the cardiovascular benefit of these supplements has never been proven by population-based scientific studies.
"I hope our study will get people to discuss the use of multivitamin supplements with their physicians, and reallocate their resources to something that is proven to work, like fruit and vegetable intake and exercise."
The researchers analysed 18 studies that were published by the American Heart Association journal Circulation.
After looking at the data, they found there was no benefit to heart health after taking vitamins.
"We meticulously evaluated the body of scientific evidence," said Dr Kim, assistant professor of cardiology in the Department of Medicine.
"We found no clinical benefit of multivitamin and mineral use to prevent heart attacks, strokes or cardiovascular death."
Dr Kim has called for people to protect their heart health by using measures that have been proven to reduce risk.
"Although multivitamin and mineral supplements taken in moderation rarely cause direct harm, we urge people to protect their heart health by understanding their individual risk for heart disease and stroke and working with a healthcare provider to create a plan that uses proven measures to reduce risk," Dr Kim said.
"These include a heart-healthy diet, exercise, tobacco cessation, controlling blood pressure and unhealthy cholesterol levels, and when needed, medical treatment."
Chief medical officer for prevention from the American Heart Association, Eduardo Sanchez, said the study was a vital wakeup call.
"Eat a healthy diet for a healthy heart and a long, healthy life," Dr Sanchez said.
"There's just no substitute for a balanced, nutritious diet with more fruits and vegetables that limits excess calories, saturated fat, trans fat, sodium, sugar and dietary cholesterol."