Study: Vitamin Supplements Don’t Provide Health Benefits

CONTRARY TO POPULAR belief, vitamin and mineral supplements provide neither added value nor added risk in the prevention of cardiovascular disease, heart attack, stroke or premature death, anew study found.

Published Monday in the Journal of the American College of Cardiology, the findings were based on a study of trials conducted from January 2012 to October 2017 and found vitamin D, calcium and vitamin C did not help in preventing cardiovascular disease, heart attack, stroke or premature death. Although a 1993 study linked vitamin E to a lower risk of coronary heart disease, this study showed various other vitamins do not benefit patients but do no harm either, according to lead author Dr. David Jenkins.

Jenkins says it was surprising vitamin D, in particular, does nothing for lengthening or shortening one's lifespan, nor does vitamin C. 

"We looked at whether vitamins are good for cardiovascular disease and all-cause mortality," Jenkins says. "We asked whether micronutrients could shorten or lengthen your life. But we didn't look into vitamin C in attenuating colds – which it probably does."

Of the vitamins analyzed were vitamins A, B1, B2, B3 (niacin), B6, B9 (folic acid), C, D and E, as well as beta carotene, calcium, iron, zinc, magnesium and selenium, according to the study. The term multivitamin "has been used to denote the use of supplements that include most vitamins and minerals." The study confirmed folic acid and B vitamins "seem to prevent stroke, possibly if you're deficient," Jenkins says, referencing a previous study conducted in China. On the other hand, niacin and antioxidants showed a very small effect on mortality from any cause.

For people who are not vitamin deficient, the old adage that one should eat their fruits and vegetables every day has proven true. According to Marion Nestle, nutrition, food studies and public health professor at New York University, a healthy diet contains enough vitamins and provides them in the right proportions for good health.

"Vitamin supplements are powerful placebos," Nestle says. "People feel better when they take supplements in the belief that taking more vitamins will improve health. Most evidence shows that they do not."

If a physician recommends supplements or vitamins to a patient who is deficient, they shouldn't refrain from taking them. But a diet with fruits, vegetables, legumes and nuts contains a lot of the nutrition the average person needs, according to Jenkins, and supplements are, more often than not, unnecessary.

"I don't want people to say, 'I can take supplements instead of a good diet,'" Jenkins says. "Supplements are not the answer for a good diet."