| Test | Expected value in pediatric patients with iron deficiency anemia* | Confounding factors |
| Hemoglobin[1] | <11 g/dL (6 months to <5 years old) <11.5 g/dL (5 to <12 years old) <12 g/dL (12 to <15 years and nonpregnant females ≥15 years) <13 g/dL (males 15 years and older) | Viral infections may cause a transient decrease in hemoglobin |
| MCV | <70 fL (1 to <12 years old) <80 fL (12 years and older) | Thalassemia trait; hemoglobin E |
| RDW | >15.8% | Infection or inflammation, hemolysis |
| Erythrocyte protoporphyrin¶ | >70 to 80 mcg/dL | Lead poisoning¶ |
| TIBC | >450 mcg/dL | Liver disease, inflammation, or hemolysis may lower TIBC; pregnancy or hormonal contraceptives may increase TIBC |
| Transferrin saturation | <12 to 15% | Infection or inflammation |
| Serum ferritin | <15 ng/mL | Infection or inflammation; liver disease |
| sTfR | >27.3 nmol/L | Increased in high turnover states |
| Serum iron | <30 mcg/dL | Diurnal variation; iron intake; infection or inflammation |
| Reticulocyte hemoglobin content (CHr) or equivalent (Ret-He)[2] | <27 pg | Also decreased in thalassemia and thalassemia trait |
MCV: mean corpuscular volume; RDW: red cell distribution width; TIBC: total iron-binding capacity; sTfR: soluble transferrin receptor.
* These values are estimates for most children and adolescents with iron deficiency anemia. More precise standards for each age group are outlined in other UpToDate tables and topics on anemia in children.
¶ Erythrocyte protoporphyrin levels usually are not elevated until lead levels are markedly elevated. Thus, it is not a good screening test for mild lead toxicity and is not recommended for screening for pediatric lead poisoning.