Melons are low in calories, with just 64 calories in a 1-cup serving of honeydew balls and fewer calories in cantaloupe, casaba or watermelon balls. At the same time, melons are high in essential vitamins and minerals. They contain almost no fat or saturated fat, making them an excellent choice for snacks or a side dish. Vitamin A is important for healthy teeth, skin, bone and mucous membranes. It helps the vision system by promoting retinal health. Insufficient vitamin A may lead to poor functioning of the immune system. Cantaloupe is high in vitamin A, with more than 25 percent of the recommended daily amount in a 1-cup serving. Vitamin C is an antioxidant vitamin that plays an important role in the growth and maintenance of all tissues in your body. It functions in wound healing and repair of cartilage, bones and teeth. Adults should receive 90 mg per day of vitamin C. A 1-cup serving of cantaloupe provides 65 mg of vitamin C. One cup of casaba melon provides 37 mg of vitamin C, and honeydew provides 30 mg.