“What we see is quite emphatically that there isn’t a big effect,” said Dr. David Jenkins, the study’s lead author and a Canada Research Chair in the department of nutritional sciences at the University of Toronto.
In fact, experts say, you’re better off spending your vitamin money at the grocery store.
And it’s a lot of money. Just under half of Canadians take some kind of supplement, according to Statistics Canada. Women are more likely to take them than men.
For this analysis, researchers from Toronto’s St. Michael’s Hospital examined studies on multivitamins and a long list of common supplements like Vitamin D and beta-carotene and found that they made almost no difference when it came to cardiovascular disease or all-cause mortality.
The only thing that may have made a difference was that folic acid seemed to be linked to having fewer strokes and less overall cardiovascular disease.
However, Jenkins noted that the study that looked at this focused on China. Unlike Canada, China doesn’t fortify its flour with folic acid. So, it’s possible that the folic acid supplements were just correcting a vitamin deficiency in that population. A similar, though lesser effect was noticed in B-complex vitamins, which include folic acid.
Joe Schwarcz, director of McGill University’s Office for Science and Society, said that this study was well-designed and thorough, but its results aren’t surprising to anyone who has studied vitamins.
“There really is no significant benefit from taking supplements,” he said.
He noted that antioxidants might even cause harm, according to the evidence presented in this paper. There was a slight increase in all-cause mortality. “That doesn’t mean that the antioxidants cause people to die earlier. What I think it could mean is that people who already have some kind of existing disease are more likely to take antioxidants.”
He also noted that this particular paper only examined overall mortality and cardiovascular disease, not other conditions.
For James McCormack, a professor in the faculty of pharmaceutical sciences at the University of British Columbia, this paper shows nothing new. “It shows what we’ve known for years: that these vitamins do little to nothing.”
People should consider checking with their doctors to see if they’re vitamin-deficient before they take a supplement, said Jenkins. And there are some conditions or situations, like taking folic acid during pregnancy, for which certain supplements are recommended.
“If you’ve not been taking any fruits and vegetables and you start getting bleeding gums, obviously nobody’s going to start saying don’t take vitamin C,” he said.
Jenkins, Schwarcz and McCormack all say the same thing: the best way to get vitamins is by eating a healthy diet.
“The moral of the story is eat your fruits and vegetables. Don’t expect to get benefits from a pill,” Schwarcz said.