The paper – published in the Journal of the American College of Cardiology – showed that multivitamins, vitamin D, calcium and vitamin C had no effect on the risk of developing cardiovascular disease, heart attack, stroke, or premature death from any cause.
"We were surprised to find so few positive effects of the most common supplements that people consume," the study's lead author Dr David Jenkins, a professor of nutrition science and medicine at St Michael's Hospital in Toronto, said 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."
However, the study did find that folic acid alone and B-vitamins with folic acid may reduce cardiovascular disease and stroke. But before you start stockpiling these supplements, in a piece for The Conversation dietitian Clare Collins has highlighted that of the studies testing folic acid supplements, stroke was reduced in only two of the seven “gold-standard” studies. One of which was a study of 20,000 people in China, a country does not have a folic acid food fortification program that adds the vitamin to breads and cereals like Australia does.
The review also found that antioxidant mixtures with niacin showed an increased risk for all-cause mortality, which researchers say might be related to its negative effects on glycemic response.
The researchers suggest that people focus on eating a nutrient rich diet of whole foods to get the vitamins and minerals your body requires, rather than using supplements as an “insurance policy”.