A new study from the National Institutes of Health (NIH), Office of Dietary Supplements (ODS), found a significant association in reducing death from cardiovascular disease (CVD) among multivitamin users versus non-users, when the supplements were taken for three or more years. The results were particularly apparent among women, with no association found for men. The study, “Multivitamin-Mineral Use Is Associated with Reduced Risk of Cardiovascular Disease Mortality among Women in the United States,” was published in The Journal of Nutrition this month.
To reach their conclusions, the study authors analyzed data from the government’s NHANES survey, including a final study sample of 8,678 adults, 40 years and older, excluding, among others, those participants with a history of CVD.
The results reinforce findings from a large prospective cohort study of women in Sweden published in 2010 that showed an association with a reduced risk of myocardial infarction in women who used multivitamins, with the strongest association in that study found in those women taking multivitamins for more than five years.
According to Duffy MacKay, N.D., senior vice president, scientific and regulatory affairs, Council for Responsible Nutrition (CRN), “We find these results encouraging and they provide another potential reason for women to take their multivitamins. But people should not expect that taking a multivitamin in and of itself will prevent heart disease; we advise people to take their vitamins as just one of the smart choices they make for good health.”
An interesting question about the study is why the results were positive for women, but null for men. Dr. MacKay noted the fluidity of scientific research, stating “Just when you think you have an answer, another study either reinforces that answer, or takes you in a different direction. That’s why it’s important to both look at the body of research, and to keep building on that research. We commend ODS for recognizing that, and we urge researchers to continue this kind of research to generate new hypotheses as well as find more answers.”
Despite the results of the study findings for men, Dr. MacKay’s advice for both sexes when it comes to multivitamins remains the same. “In general, I tell my patients to take a multivitamin. It’s a convenient and affordable way to ensure you’re getting the nutrients you need, and we know from government data that most Americans fall short in getting appropriate amounts of essential nutrients. And, there is good research that demonstrates potential benefit for the multivitamin in men and cancer prevention, which I would consider the icing on top of the cake.”
Beyond the actual study results, Dr. MacKay pointed out he was pleased to see that the authors raised another important issue relevant to researchers, academics and others seeking to interpret scientific results—that while, according to the authors, “randomized controlled trials (RCTs) represent the gold standard study design in research, the external validity of these RCTs is limited.” Said Dr. MacKay, “There is on-going discussion in the nutrition research community as to what is the best way to study nutrition—and RCTs have limitations in this area. They provide an extremely targeted but narrow perspective, and as a result, may not necessarily translate into practical advice for consumers. That’s why it’s important for researchers not to rely solely on RCTs for studying nutrition. We’re pleased to see the study authors make this point, and are gratified that this discussion continues in the scientific, academic and research communities.”