Vitamin and mineral supplements do not lead to measurable health benefits, a new study published in the journal Journal of the American College of Cardiology reports.
This research — which comes from scientists at the University of Toronto — shows that multivitamins, as well as vitamin D, calcium, and vitamin C supplements have no positive or negative health effects when taken over long periods of time.
To make that discovery, the team analyzed more than 150 randomized clinical trials published between January 2012 and October 2017. They found that, not only did the supplements have no positive effects, but Niacin (B3) and antioxidants seemed to increase the risk of death.
For example, there were 2,908 deaths among 18,719 people who took vitamin D, compared to 2,968 deaths among 18,831 people in control groups.
“We were surprised to find so few positive effects of the most common supplements that people consume,” said lead author David Jenkins, a professor at the University of Toronto, in a statement. “Our review found that if you want to use multivitamins, vitamin D, calcium or vitamin C, it does no harm—but there is no apparent advantage either.”
This is not the first time medical professionals have questioned supplements. Previous studies show that there is not enough evidence on the benefits or harms of multivitamins to prevent cardiovascular disease or cancer.
That is important because current estimates show that roughly 50 percent of Americans take at least one vitamin supplement and at least 30 percent take multivitamins.
Though such products do not do any known damage, the fact that they come with no benefits means they are not a good substitute for healthy foods.
“In the absence of significant positive data—apart from folic acid’s potential reduction in the risk of stroke and heart disease—it’s most beneficial to rely on a healthy diet to get your fill of vitamins and minerals,” concluded Jenkins, according to Gizmodo. “So far, no research on supplements has shown us anything better than healthy servings of less-processed plant foods including vegetables, fruits, and nuts.”