Oranges are highly valued for their vitamin C content. It is a primary source of vitamin C for most Americans. This wonderful fruit has more to offer nutritionally than just this one nutrient, containing sufficient amounts of folacin, calcium, potassium, thiamin, niacin and magnesium. Most of the consumption of oranges is in the form of juice. Eating the whole fruit provides 130% of the recommended dietary allowance for vitamin C, less than the juice, but more fiber, which is not present in the juice.