In adults in the United States, iron deficiency anemia is most likely the result of chronic blood loss. Chronic blood loss in conditions such as colon cancer depletes iron stores. In infants, however, iron deficiency anemia is commonly related to issues with diet or absorption of iron. Iron deficiency anemia due to malnutrition is not commonly seen in the United States.
Breastfeeding without starting iron supplementation by six months of age is a known risk factor for infants and is seen in this patient. Most commonly, infants do not have any symptoms of anemia when iron deficiency is found. Routine screening for iron deficiency is commonly performed between 6-24 months of age.
Review of common iron study analytes:
| Term | Definition |
| Ferritin | A protein that stores iron. |
Transferrin
| A protein that transports iron. |
| Total iron binding capacity (TIBC) | The number of binding sites available for iron on the transferrin protein. |
| Erythrocyte/zinc protoporphyrin | A compound formed when zinc binds to the RBC component protoporphyrin. In normal iron-sufficient states, iron is bound to protoporphyrin. Zinc binds to protoporphyrin when iron is deficient, forming zinc protoporphyrin which can be assayed. Note: This is one of the earliest indicators of iron deficiency. |
