TORONTO — Taking multivitamins or other commonly consumed vitamin and mineral supplements won’t actually provide you any health benefits, but they won’t harm you either, a new study finds.
Researchers from the University of Toronto and St. Michael’s Hospital conducted a review of 179 studies on popular vitamin supplements that were published between January 2012 and October 2017.  Studies covered a vast spectrum of supplements, including vitamins A, B1, B2, B3 (niacin), B6, B9 (folic acid), C, D and E; and mineral supplements β-carotene; calcium; iron; zinc; magnesium; and selenium. Multivitamins that contained a wide variety of the vitamins and minerals were also reviewed.
The research team concluded that the most commonly consumed supplements — multivitamins, vitamin D, calcium, and vitamin C — had no effect on a person’s risk of suffering a heart attack stroke, heart disease, or early death.
“We were surprised to find so few positive effects of the most common supplements that people consume,” notes Dr. David Jenkins, the study’s lead author, 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.”
The only supplements that showed any benefit among the studies were folic acid or B-vitamins that contained B6, B12, and folic acid, which could lower one’s risk of heart disease and stroke. Folic acid alone showed a 20 percent lowered risk of stroke. Conversely, the review found that niacin and antioxidants had a “very small” effect that could potentially raise the risk of death from any cause.
The authors say it’s best to stick to a healthy diet that includes plenty of fruits and vegetables which naturally provide our bodies with vitamins and minerals.
“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,” says Dr. Jenkins. “So far, no research on supplements has shown us anything better than healthy servings of less processed plant foods including vegetables, fruits and nuts.”
Jenkins says it’s important that people be aware of what types of supplements they’re taking and to always consult a doctor, particularly if they have any specific deficiencies.
“These findings suggest that people should be conscious of the supplements they’re taking and ensure they’re applicable to the specific vitamin or mineral deficiencies they have been advised of by their healthcare provider,” adds Jenkins.
According to the National Health and Nutrition Examination Survey, in 2012, it was estimated that 52 percent of the population were taking supplements.
The full study was published in the June 5, 2018 edition of the Journal of the American College of Cardiology. It was funded by the Canada Research Chair Endorsement, Loblaw Cos. Ltd., and the Canadian Institutes for Health Research.
