Vitamin C is a water-soluble vitamin that cannot be made by the body and must be obtained from foods or other sources. Vitamin C is found in abundance in citrus fruits, such as oranges, grapefruit, and lemons, as well as in green leafy vegetables, potatoes, strawberries, bell peppers, and cantaloupe. Its scientific or medical name is ascorbic acid or ascorbate. Vitamin C supplements are available in powder or chewable pill form. Vitamin C is known to be an antioxidant, blocking the action of free radicals that can damage cells, and is an important component of intracellular matrices and connective tissue. Vitamin C supplements have been tested as an intervention for diarrhea and fatigue in patients with cancer. Topical vitamin C has been studied in patients with cancer for effectiveness in the prevention and treatment of radiodermatitis.