The recommended daily allowance for vitamin C in healthy male's age 19 to 30 years old is 90 milligrams a day. For healthy females age 19 to 30 years old is 75 milligrams a day. Vitamin C is a powerful antioxidant which helps prevent cancer, boost your immunity, and is great for your skin. Foods that are high in vitamin C are really colorful so, look for the brightly colored fruits and vegetables such as citrus fruits, dark leafy greens, papayas, kiwis, and oranges. Other fruit you may not know about is called acerola, also known as a West Indian cherry. In Brazil, you can find acerola juice on every corner and this is one of my favorite drinks. If you're feeling run-down and you're unable to get vitamin C from your food sources, it might be a good idea to consider taking a vitamin C supplement as a good solution.