AMA’s Position on Nutritional Supplements:

Vitamins for Chronic Disease Prevention in Adults


Take Multivitamins Urges American Medical Association
August 31,2002

Reversing a long-standing anti-vitamin policy, The Journal of the American Medical Association today is advising all adults to take at least one multivitamin pill each day.

Scientists' understanding of the benefits of vitamins has rapidly advanced, and it now appears that people who get enough vitamins may be able to prevent such common chronic illnesses as cancer, heart disease and osteoporosis, according to Drs. Robert Fletcher and Kathleen Fairfield of Harvard University, who wrote the new guidelines. The last time JAMA made a comprehensive review of vitamins, about 20 years ago, it concluded people of normal health shouldn't take multivitamins because they were a waste of time and money. People can get all the nutrients they need from their diet, JAMA advised, adding that only pregnant women and chronically sick people may need certain vitamins.

That was at a time when knowledge about vitamins was just beginning to expand. The role that low levels of folate, or folic acid, play in neural tube defects, for instance, was not known, nor was its role as a major risk factor for heart disease.

Researchers hope JAMA's endorsement will encourage more people to reap health benefits of a daily multivitamin.

Health experts are increasingly worried that most American adults do not consume healthy amounts of vitamins in their diet, although they may be getting enough to ward off such vitamin-deficiency disorders as scurvy, beriberi and pellagra.

Almost 80 percent of Americans do not eat at least five helpings of fruits and vegetables a day, the recommended minimum amount believed to provide sufficient essential nutrients. Humans do not make their own vitamins, except for some vitamin D, and they must get them from an outside source to prevent metabolic disorders.

"It's nice to see this change in philosophy that's saying we can make public-health recommendations based on this really compelling set of data," said Dr. Jeffrey Blumberg, chief of antioxidant research at Tufts University's Jean Mayer USDA Human Nutrition Research Center on Aging.

Blumberg said the JAMA recommendations underscore a growing concern among nutrition experts that the recommended daily allowances, or RDAs, for many vitamins are set too low. RDAs essentially were established to prevent symptoms of vitamin-deficiency disorders, he said. But evidence is growing that higher levels of many vitamins are necessary to achieve optimum health, he said. The National Academy of Sciences, which sets RDAs, is revising its recommendations based on the new evidence.

Even people who eat five daily servings of fruits and vegetables may not get enough of certain vitamins for optimum health, Fletcher said. Most people, for instance, cannot get the healthiest levels of folate and vitamins D and E from recommended diets, he said. "All of us grew up believing that if we ate a reasonable diet, that would take care of our vitamin needs," Fletcher said. "But the new evidence, much of it in the last couple of years, is that vitamins also prevent the usual diseases we deal with every day - heart disease, cancer, osteoporosis and birth defects."