According to TheCritical Reviews in Food Science and Nutrition, the RDA of vitamin C(Ascorbic acid) should be 200 mg/day in an adult diet. The higher levels of vitamin C not only preventscurvy, it also helps reduce chronic diseases such as the heart disease,stroke, cancer, & the underlying issues that lead to them, such as hypertension (high BP), chronicinflammation, poor immune response & atherosclerosis. The daily diet of an adult must include 5-9 daily servings of fruits and raw/ steam-cooked vegetables, with a 6 ounce glass of orange juice. This would provide 200 mg of vitamin C a day. Citrus fruits, strawberries, green peppers, broccoli, sweet & white potatoes are also the excellent sources of vitamin C.The intake of vitamin C on a daily basis poses no risk, but there is strong evidence that it would provide multiple & substantial health benefits. Source: HerbHealtH