Commonly used vitamin and mineral supplements do not have any consistent benefits, according to a new study.
Researchers in Canada found that supplements such as multivitamins, vitamin D, calcium and vitamin C – which are taken to add to nutrients found in food – provide no protection against heart disease, heart attack, stroke or premature death.
Only folic acid, along with B-vitamins containing folic acid, were found to potentially reduce the risk of cardiovascular disease and stroke.
The team at St Michael’s Hospital and the University of Toronto looked at 179 controlled trials published between January 2012 and December 2017.
The studies investigated the effects of vitamins and mineral supplements (A, B1, B2, B3 or niacin, B6, B9 or folic acid, C, D, and E, as well as beta-carotene, calcium, iron, zinc, magnesium and selenium) on the risk of cardiovascular disease, heart attack, stroke or premature death.
The team found that overall, the supplements had no beneficial effect on health, although they were not found to be harmful either.
Dr David Jenkins, the study’s lead author, said: “We were surprised to find so few positive effects of the most common supplements that people consume.
“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.”
In addition, the meta-analysis also revealed that niacin and antioxidants had a very small effect which, according to the researchers, “might actually signify an increased risk of death from any cause”.
Dr Jenkins added: “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.
“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.”
The results are published in the Journal of the American College of Cardiology.