The main properties of this fruit have a lot to do with its vitamin C: it provides all the vitamin C that is needed for the day. This nutrient is essential for resistance to infections (orange juice is the most widely used natural resource to prevent colds and flu); it increases the absorption of iron, calcium and phosphorus and has antioxidant properties.
But vitamin C is not the only interesting component. The fiber gives the orange digestive properties and the flavonoids collaborate with the vitamins in reinforcing the immune system.
Oranges are also rich in thiamin and folic acid, two B vitamins essential for a healthy nervous system.