Multivitamins don’t prevent heart attacks, strokes, or CV death

Taking multivitamin and mineral supplements doesn’t prevent heart attacks, strokes, or cardiovascular death, according to the results of a new meta-analysis published in Circulation: Cardiovascular Quality and Outcomes.

“We meticulously evaluated the body of scientific evidence,” said lead author Joonseok Kim, MD, assistant professor of cardiology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL. “We found no clinical benefit of multivitamin and mineral use to prevent heart attacks, strokes, or cardiovascular death.”

Dr. Kim and colleagues reviewed results from 18 prospective cohort studies and randomized controlled trials, which involved a total of more than 2 million participants with an average of 12 years of follow-up. They found that multivitamin and mineral supplementation wasn’t associated with mortality due to cardiovascular disease (CVD), coronary heart disease (CHD), or stroke, nor with incidence of stroke.

However, multivitamin use was associated with a 12% lower relative risk of CHD incidence, but this result was primarily driven by observational studies and didn’t remain significant in the pooled subgroup analysis of randomized controlled trials.

“Our study supports present guidelines that recommend against the routine use of multivitamin/mineral supplements to promote cardiovascular health,” Dr. Kim and coauthors concluded.

About 31% of Americans use multivitamin and mineral supplements, according to 2011-2012 data from the National Health and Nutrition Examination Survey. While several population studies have suggested that multivitamin and mineral supplements may be beneficial for certain cardiovascular outcomes, most other studies showed no significant cardiovascular benefit, the researchers noted.

“Although multivitamin and mineral supplements taken in moderation rarely cause direct harm, we urge people to protect their heart health by understanding their individual risk for heart disease and stroke and working with a health-care provider to create a plan that uses proven measures to reduce risk,” Dr. Kim said. “These include a heart-healthy diet, exercise, tobacco cessation, controlling blood pressure and unhealthy cholesterol levels, and when needed, medical treatment.”

Why has the notion that multivitamins benefit CV health been so persistent?

In an accompanying editorial, Alyson Haslam, PhD, Division of Hematology Oncology, Knight Cancer Institute, Portland, OR, and Vinay Prasad, MD, MPH, Department of Public Health and Preventive Medicine, Oregon Health & Science University, Portland, OR, wrote: “Often in biomedicine, practices are adopted because they appeal to our hopes and there is biological plausibility. In the case of multivitamins, it is logical that some vitamins may reduce cardiovascular events because they are anti-inflammatory or more broadly improve health and well-being. Yet, in this case, it appears they do not, and as such, multivitamins for cardiovascular disease joins the list of plausible but failed practices in cardiology.”