Based on the text, here are three true statements about iron and its sources:
1. The human body needs iron to produce hemoglobin, which helps red blood cells transport oxygen.
2. Dietary sources of iron include both plant sources (such as vegetables and beans) and animal foods (including poultry, red meat, and fish).
3. The iron in animal foods, called heme iron, is more easily absorbed by the human body compared to the iron in plant sources, called nonheme iron.