The most popular vitamin and mineral supplements that people take make no difference to a person’s health, a five-year study has revealed, surprising even the researchers, who expected to find at least some positives.
According to the research that ran from 2012 to 2017, the most consumed supplements – vitamin C, vitamin D, calcium, and multivitamins – did nothing to prevent heart attacks, strokes, cardiovascular disease, or death.
"We were surprised to find so few positive effects of the most common supplements that people consume," said 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 study, published in the Journal of the American College of Cardiology, did, however, demonstrate a relatively small benefit in taking folic acid and B-vitamins (reducing risk of cardiovascular disease and death), and even a slight increased risk in antioxidant mixtures and niacin (which lowers cholesterol but can raise blood sugar levels).
There was no evidence that vitamins C and D, calcium, and beta-carotene made any difference at all to reducing risk of heart disease, stroke, or influenced longevity.
So what does that mean?
The authors were keen to stress in the study that the treatment of micronutrient deficiencies in the last 200 years is one of medicine’s greatest achievements. However, the emphasis has shifted to using them as preventative measures, with no evidence to support that, and increasingly as some kind of promise of overall health and long life – again, of which there is no evidence for.
Past studies have shown that an excess of minerals and antioxidant supplements actually cause deficiencies in other important minerals such as zinc and iron by preventing the body from naturally absorbing them through food.
And, of course, this isn't the first time researchers have demonstrated there are no real advantages to taking multivitamins and minerals unless you specifically need to: you can read past studies here, here, and here showing that.
The bottom line is there is no shortcut to a healthy diet, other than actually having a healthy diet. Take supplements for any micronutrient deficiencies you have on your doctor's recommendation, but if anyone is selling you on the all-encompassing benefits of already easily accessible vitamins, it’s more likely they have a bigger interest in your wallet than your health.
"So far, no research on supplements has shown us anything better than healthy servings of less processed plant foods including vegetables, fruits, and nuts," Dr Jenkins said.