Final answer:
Oranges are a good source of vitamin C, and adolescents are recommended to include a variety of fruits and vegetables in their diet, with citrus fruits being particularly rich in vitamin C. Vitamin C is important for preventing certain diseases and aiding the absorption of iron.
Step-by-step explanation:
The school nurse should instruct the adolescents that oranges are a good source of vitamin C. Citrus fruits like oranges are rich in this essential nutrient, which acts as an antioxidant and is crucial for the prevention of diseases such as scurvy. Adolescents should be encouraged to include a variety of fruits and vegetables in their diet, aiming for at least three to five servings of vegetables and fruits each day to meet their nutritional needs. Vitamin C also aids in the absorption of iron from the intestine and can reduce the duration and severity of the common cold.
While all fruits and vegetables can contribute to an overall healthy diet, for vitamin C specifically, citrus fruits like oranges, lemons, and limes stand out. It should be noted that other sources of vitamin C include fresh green vegetables, cabbage, lettuce, guavas, berries, melons, and tomatoes. Adolescents may also choose to drink 100 percent fruit juice in moderation as a part of their fruit intake.