For many individuals, taking a multivitamin is a daily ritual as common as brushing one's teeth. Americans spend $23 billion a year on multivitamins. Recent articles in newspapers such as The New York Times, Wall Street Journal and The Boston Globe, however, have left some Americans questioning how useful this habit really is.
The answer is that multivitamins may not be a silver bullet for various ailments but are an important component of many diets, according to Jeffrey Blumberg, the director of the Antioxidants Research Laboratory at the Jean Mayer United States Department of Agriculture (USDA) Human Nutrition Research Center on Aging and professor at the Friedman School of Nutrition Science and Policy.
Most recent articles regarding multivitamin usage question whether vitamins can prevent chronic illnesses. Blumberg thinks they are asking the wrong question. "I mean, do multivitamins prevent cancer? Do they prevent heart disease? Do they prevent major illness and death?" he said. "Well, no, and by and large, I don't think most responsible manufacturers of multivitamins ever particularly claim they did."
Blumberg said he believes that multivitamins do meet their advertised goal of helping users meet their recommended intake of vitamins and minerals; but the question of whether one gains anything from taking a dietary supplement cannot definitively be answered without a careful examination of the subject and his or her diet.
Freshman Lauren Klinker, a member of the women's crew, explained that she currently takes fish oil and vitamin C supplements but stopped taking a multivitamin a while ago. "I stopped and I feel no different," she said. "I think if you just eat healthily, you don't need that."
Blumberg reiterated this idea, noting that if one strictly follows the dietary guidelines for Americans, he or she might not gain anything from taking a multivitamin. "The problem is that three percent of Americans have been found to follow the dietary guidelines," he said. "I think it's reasonable that taking a multivitamin ... will help you meet all of the essential vitamins and minerals that you require."
The Journal of the American Medical Association's official stance recommends that adults take a multivitamin supplement. "Whenever I go in for a checkup at the doctor's, they always ask if I've been taking multivitamins, so it seems like that's still a good thing," junior Nadine Kesten, head of the Public Health at Tufts group, said. "I haven't heard anything other than that they've been good for you."
Recent headlines about multivitamins have focused on claims that taking daily multivitamins can reduce the risk for conditions like heart disease and cancer. Observational studies of large populations seem to indicate that this might be the case, but clinical trials have not held up according to Blumberg.
"It's really hard to do observational studies ... because you'll find that people that practice positive proactive health behaviors [often] eat well, they exercise, they wear seatbelts, they see their doctor on an annual visit, and they take a multivitamin," he said. "We know that positive health behaviors cluster together."
Another problem with multivitamin clinical studies, according to Blumberg, is that nutritionists are often more concerned with studying the effects of specific nutrients rather than studying the broad combination of nutrients found in a multivitamin. "We want [our hypotheses] to be a bit more elegant and clean," he said.
Despite the difficulties with studying multivitamins, Blumberg believes that researchers should continue their efforts, especially because of vitamins' extreme popularity in the United States.
Physicians' Health Study II, a research project which is still underway, has been attempting a controlled test since 1997. The study focuses on physicians because they were deemed to be a group that was likely to be compliant with the study. It was scheduled to end in 2007 but was extended for a few more years. The study has not found thus far that vitamin C and E supplements prevent heart disease or cancer.
"What we do know is the American diet ... is rich in calories but relatively poor in the essential nutrients including vitamins and minerals," Blumberg said. American dietary guidelines have, according to Blumberg, "nutrients of concern. These are nutrients where half of the American population is meeting less than half of their requirement from diet." Included in the list of nutrients of concern are vitamins A, C, E, potassium, magnesium and dietary fiber.
But multivitamin supplements are not the entire answer. "I think it's important to understand that a dietary supplement is what it says it is: It's a supplement, not a substitute for your diet," he said. "So you can't eat a lousy diet and think that taking a multivitamin, or any supplement, is going to address all of your problems."
