Iron is an important nutrient for people to eat, so scientists want to learn more about it. Still, many people, particularly women and young children, often don't get enough iron in their diet.
Without enough iron, you don't form enough red blood cells and thus don't get enough oxygen. You could then have a condition called anemia (ah-nee-mee-ah) that makes you weak, tired, pale and cranky.
It is especially important for mothers to get enough iron when they are going to have a baby so that the baby is healthy.