Experts Say: Up the Vitamin C RDA

CHICAGO—A cup of fresh orange juice contains 124 mg of vitamin C—twice the current recommended dietary allowance (RDA). While the RDA may be enough to prevent deficiency diseases, is it enough for optimum health?

Mark Levine, M.D., of the National Institutes of Health in Bethesda, Md., and colleagues recommend the RDA for vitamin C be raised from 60 to 100­200 mg. The revised recommendations for vitamin C intake are based on new data, new criteria for devising recommendations and new Dietary Reference Intake guidelines, Levine writes in an article published April 22 in The Journal of the American Medical Association.

A recommendation of 200 mg from five servings of fruits and vegetables daily will make the intake requirements similar to those of the United States Department of Agriculture and the National Cancer Institute. For those unable or unwilling to get their daily vitamin C from food, the authors recommend a 200-mg supplement.