Vitamin C is a water soluble vitamin so we must consume it on a regular basis because excess is excreted in the urine. Vitamin C is also an antioxidant. Like vitamin E, it donates electrons to free radicals to prevent damage of cells and tissues.
The RDA for vitamin C is 90 mg per day for men and 75 mg for women. The RDA for smokers is 35 mg more per day than nonsmokers. Other situations that may increase the need for vitamin C include healing from a traumatic injury, surgery, or burns and the use of oral contraceptives among women.
Fruits and vegetables are the best sources of vitamin C. Because heat and oxygen destroy vitamin C, fresh sources have the highest content. Cooking foods also leaches their vitamin C which is then lost when straining them. Citrus fruits, potatoes, strawberries, tomatoes, kiwi fruit, broccoli, spinach, cabbage, green and red peppers and cauliflower are excellent sources of vitamin C. Fortified beverages and cereals are also good sources. Dairy foods, meats, and nonfortified cereals and grains provide little or no vitamin C. By eating the recommended amount of vegetables and fruits a day, the body will meet the required amount of vitamin C.
Because vitamin C is water soluble, we usually excrete any excess. Consuming excess food sources doesn’t lead to a toxicity, only supplements can. Taking megadoses of vitamin C is not fatally harmful but side effects exceeding 2,000 mg a day can include nausea, diarrhea, nosebleeds, and abdominal cramps.
Source: Thompson, Janice, Melinda Manore, and Linda A. Vaughan. The Science of Nutrition. San Francisco, CA: Pearson Benjamin Cummings, 2011. Print.