Vitamin C is also called ascorbic acid, which is the form of vitamin C found in most foods. It is a water-soluble vitamin and cannot be stored in the body. Most plants and animals can produce their own vitamin C, but humans cannot. For this reason, humans must eat ample amounts of vitamin C every day.
Vitamin C is also a powerful antioxidant that helps boost the body immune system, which is why people often eat oranges or a Vitamin C supplement to prevent colds.