New research is questioning the benefits of taking supplemental vitamins and minerals, suggesting that, for the general population, such supplements may actually pose more risks than benefits. It's a disconcerting finding since, according to a study just published in the Archives of Internal Medicine, 85 percent of women surveyed reported use of supplements. And the news, no doubt, has implications for consumers, who currently spend $20 billion a year on something that may be doing more harm than good.
In the study, researchers assessed over 38,000 women, aged 55 to 69, from the Iowa Women's Health Study and found a slightly higher rate of death (2.4 percent) over the study period among women who were taking vitamin and mineral supplements, compared to those who did not. This risk was particularly pronounced with the mineral iron.
Another recent study on the use of supplements found that, among over 8,000 men and women, the people who were most likely to take supplements were also those who needed them the least. This study, in The American Journal of Clinical Nutrition, reported that those individuals who took vitamins were more likely to have a healthier diet in the first place; thus, their everday diets already supplied them with the recommended daily intake values of vitamins and minerals. ACSH's Dr. Ruth Kava is not surprised by this finding. She notes, "Thanks to the Dietary Supplement Health and Education Act of 1994, supplement makers are not required to give consumers information on the evidence supporting their products safety or benefits before marketing them. This has created an industry that earns billions of dollars by convincing people that they need multivitamins, when they most likely do not.
Linking supplement use not only to a lack of benefit but to a higher level of risk is a disconcerting finding, yet ACSH's Dr. Ross is still hesitant to interpret these results as an indication that supplements are dangerous. Since this was an observational study, it cannot be used to support a cause-and-effect determination, he says. Overall, the results of these studies suggest that routinely taking supplements confers no benefit on the general population.
ACSH has written on this subject many times most recently evaluating the lack of evidence linking supplement use in the general population to any health benefits. As ACSH's Dr. Elizabeth Whelan summarizes, "Supplements offer risks and little benefit. It's really a phenomenal conclusion, given that supplement makers have spent decades advocating greater supplement use. At ACSH, we've always been against recommending supplements for the general population not because they're harmful, but simply because there's no evidence that they are beneficial either.