Final answer:
Oral iron should be administered on an empty stomach to ensure proper absorption and effectiveness of the treatment.
Step-by-step explanation:
When administering oral iron for a child with iron deficiency anemia, the nurse instructs the mother to administer the iron on an empty stomach.
Iron absorption is enhanced on an empty stomach, as certain substances can interfere with the absorption of iron. Taking iron with milk or dairy products, antacids containing aluminum, or citrus juice can reduce the absorption of iron.
It is important for the child to take the iron as instructed to ensure proper absorption and effectiveness of the treatment.