According to Mark Moyad, MD, MPH, of the University of Michigan, adults need 500 mg of Vitamin C daily to stay healthy. While its RDA is only 75-90 mg daily. Unfortunately, only 10%-20% of adults meet this requirement through nine servings of fruits and vegetables every day. Because of this fact, Moyad recommends a daily dose of a non-acidic (prevents stomach upset) form of Vitamin C along with five servings of fruits and vegetables.

On the other hand, Dee Sanquist, spokeswoman for the American Dietetic Association, says that people should meet Vitamin C through nine servings of fruits and vegetables. Although it may be hard, the health benefits from Vitamin C as well as other minerals, vitamins, and phytochemicals in the food are more effective for disease prevention than a supplement to replace the servings.