Ideal Ferritin Range for a 9-Year-Old Boy
For a 9-year-old boy with iron deficiency symptoms, the ideal ferritin range is approximately 30 μg/L, with values below 15 μg/L confirming absolute iron deficiency and values between 15-30 μg/L indicating depleted iron stores requiring intervention. 1, 2
Age-Specific Reference Values
The CDC establishes that the average serum ferritin value for children is approximately 30 μg/L, which serves as the baseline for pediatric reference values through childhood until adolescence. 3, 1, 2 This represents the normal expected value for healthy children in this age group.
Diagnostic Thresholds for Iron Deficiency
When evaluating a 9-year-old boy with iron deficiency symptoms, use the following interpretation algorithm:
Ferritin <15 μg/L: Confirms absolute iron deficiency with 99% specificity—this is the gold standard diagnostic threshold and requires immediate iron supplementation. 1, 2
Ferritin 15-30 μg/L: Indicates low body iron stores and warrants clinical attention, even if hemoglobin remains normal. 1, 2 Iron supplementation should be strongly considered, as this represents depleted stores that can cause symptoms.
Ferritin >30 μg/L: Generally indicates adequate iron stores in the absence of inflammation. 1, 2
For children aged 6-12 years specifically, research suggests a diagnostic cut-off of 15 μg/L is appropriate, though some evidence supports using 20 μg/L for younger adolescents (12-15 years). 4
Critical Caveat: Rule Out Inflammation
Ferritin is an acute-phase protein that rises during infections, inflammation, or tissue damage, potentially masking true iron deficiency. 3, 1, 2 In the presence of inflammation, iron deficiency may be present even with ferritin levels up to 50-100 μg/L. 1, 2
When inflammation is suspected:
- Check C-reactive protein (CRP) to exclude acute phase reaction. 4
- If CRP is elevated, ferritin may be falsely elevated despite true iron deficiency. 1
- Consider calculating transferrin saturation (TSAT): values <16-20% confirm iron deficiency even with higher ferritin levels. 1
Complementary Testing Required
Do not rely on ferritin alone. 3 The complete assessment should include:
Mean corpuscular volume (MCV): A low MCV indicates microcytic anemia and, if lead poisoning and thalassemia are excluded, serves as a specific index for iron-deficiency anemia. 3
Red blood cell distribution width (RDW): A low MCV combined with RDW >14.0% indicates iron-deficiency anemia, whereas a low MCV with RDW ≤14.0% suggests thalassemia minor. 3
Transferrin saturation: Values <16-20% are sensitive markers for iron deficiency and reflect insufficient iron available for red blood cell production. 1
Clinical Significance of Low Ferritin Without Anemia
Iron deficiency can cause significant symptoms—including fatigue, reduced exercise tolerance, and impaired cognitive function—even before anemia develops. 1, 4 Low ferritin is the earliest and most specific marker of iron deficiency, reflecting depleted body iron stores before other parameters become abnormal. 1
Common Pitfalls to Avoid
Never assume normal ferritin excludes iron deficiency in the presence of inflammation. Check inflammatory markers and transferrin saturation when clinical suspicion is high. 1, 2
Do not wait for anemia to develop before treating iron deficiency. Depleted iron stores (ferritin 15-30 μg/L) warrant intervention even with normal hemoglobin. 1, 4
Avoid using adult reference ranges for children. The diagnostic thresholds differ significantly between pediatric and adult populations. 2, 4