When kids who don’t have enough iron in their blood take iron supplements for 3 months, they tend to do better on tests that measure how they think and learn.

Giving iron supplements to young kids who don’t have enough iron in their blood might help them do a little better on tests that measure how smart they are, especially in places where many kids are iron-deficient.

When kids under 7 don’t have enough iron in their blood, it can make it harder for them to think clearly and move smoothly, because their brains aren’t getting the right materials to grow and work properly.

Kids under 7 are more likely to not have enough iron in their bodies than any other group of people.

Giving kids iron supplements doesn’t reliably make them smarter or do better in school — even if their bodies absorb the iron, it doesn’t usually lead to noticeable improvements in how they think or learn.