Taking Vitamins Lowers Chronic Disease Risk

BOSTON--In a research review published in the June 19 issue of the Journal of the American Medical Association (JAMA) (287, 23:3116-26, 2002) (www.jama.com), researchers reported finding a link between inadequate intakes of certain vitamins and the increased risk for chronic conditions such as coronary heart disease, cancer and osteoporosis.

The researchers--Kathleen Fairfield, M.D., DrPH, and Robert Fletcher, M.D., both from Harvard--searched MEDLINE (a database of 11 million indexed journal citations) for English-language articles published between 1966 and 2002 that pertained to vitamins and chronic disease. Narrowing the search down to those nutrients that were considered "clinically important," the researchers honed in on data surrounding nine vitamins and chronic disease.

Vitamins B9 (folic acid) and B12 (cobalamin) were found to be necessary for homocysteine metabolism and reducing the risk of coronary heart disease. Vitamin E decreased the risk of prostate cancer, and vitamin D taken with calcium decreased the occurrence of bone fractures. However, it was found that taking excessive amounts of fat-soluble vitamins such as vitamin A may lead to more problems than were solved.

They found that the elderly, vegans, alcohol-dependent individuals and those persons suffering from vitamin malabsorption were at especially high risk for inadequate vitamin intake.

In a letter accompanying the research review, Fairfield and Fletcher report that suboptimal intake of vitamins should be seen as a risk factor for chronic diseases, especially in the elderly. In addition, most people do not consume an optimal amount of all vitamins through diet alone. "Pending strong evidence of effectiveness from randomized trials, it appears prudent for all adults to take vitamin supplements," wrote the authors. "Physicians should make specific efforts to learn about their patients' use of vitamins to ensure that they are taking vitamins they should."