Oranges are high in Vitamin C. Vitamins in food that protect us from colds and boost our immune system can be found in those foods high in vitamin C.CogniQIn addition to oranges, most citrus fruits contain high quantities of Vitamin C as do strawberries, cherries, pineapple and tomatoes. Vegetables that are also high in vitamin C include broccoli, asparagus, potatoes and cauliflower. Melons and cabbage are also found to have substantial amounts of this valuable vitamin.