Assessment of Ferritin 78 µg/L in a 9-Year-Old Child
This ferritin level of 78 µg/L does NOT indicate iron deficiency and does NOT require iron supplementation in this 9-year-old child. The transferrin saturation of 20% is at the threshold but not definitively low, and the elevated TIBC represents a normal compensatory response rather than pathological iron depletion.
Interpretation of Laboratory Values
Ferritin 78 µg/L is well above the diagnostic threshold for iron deficiency in children. The CDC guidelines establish that ferritin ≤15 µg/L confirms iron deficiency in the context of anemia, with specificity of 98% 1. More recent pediatric literature from Blood Reviews confirms that low ferritin levels are specific for iron deficiency, but this child's level of 78 µg/L is substantially elevated above any concerning threshold 1.
Transferrin Saturation Analysis
The transferrin saturation of 20% sits precisely at the diagnostic cutoff. According to the American Society of Hematology, TSAT <20% has high sensitivity for diagnosing absolute or functional iron deficiency 2. However, a TSAT of exactly 20% is borderline and must be interpreted in context with other parameters 1.
The CDC guidelines note that transferrin saturation increases throughout childhood and adolescence, and a value of 20% in a 9-year-old may represent normal developmental variation rather than pathology 1.
Elevated TIBC Significance
The elevated TIBC in this case reflects normal physiologic compensation rather than iron deficiency. TIBC increases when serum iron concentration is low as the liver increases transferrin synthesis to capture available iron 1. However, the American Society of Hematology clarifies that when ferritin is normal or elevated (as in this case with 78 µg/L), the pattern does not indicate true iron deficiency 2.
Diagnostic Algorithm
The combined interpretation of ferritin and TSAT is essential for accurate diagnosis 1:
- Ferritin <12-15 µg/L + TSAT <20% = Absolute iron deficiency requiring supplementation 1, 2
- Ferritin 30-50 µg/L + TSAT <20% = Possible early iron depletion, monitor closely 2
- Ferritin >50 µg/L + TSAT ≥20% = No iron deficiency, no supplementation needed 2
This child falls into the third category with ferritin 78 µg/L and TSAT exactly 20%.
Critical Pitfalls to Avoid
Do not supplement iron based solely on TSAT or TIBC values when ferritin is adequate. The American College of Physicians explicitly warns against iron supplementation when ferritin is normal or elevated, as this can be potentially harmful and addresses the wrong problem 3.
Ferritin is an acute-phase reactant and can be falsely elevated during inflammation, infection, or stress 1. However, at 78 µg/L without clinical signs of inflammation, this level genuinely reflects adequate iron stores rather than masked deficiency 1.
Age-Specific Considerations
Research demonstrates that diagnostic criteria for iron deficiency must be age-adjusted. Studies in infants aged 9-12 months established ferritin cutoffs of <10.9 µg/L for iron deficiency 4, while other research suggests ferritin <12 µg/L at various infant ages 5. For school-age children like this 9-year-old, ferritin levels naturally increase with age, making 78 µg/L entirely appropriate 1.
Blood Reviews notes that serum ferritin is the mainstay for assessment of total body iron stores in children, and this child's level of 78 µg/L indicates robust iron stores 1.
Recommended Management
No iron supplementation is indicated. Instead:
- Monitor clinically for symptoms of anemia (fatigue, reduced exercise capacity, pallor) 2
- Obtain complete blood count including hemoglobin, MCV, and RDW to assess for microcytic anemia if clinical concern exists 1
- Reassess in 6-12 months if dietary intake is suboptimal or growth velocity is excessive 1
- Investigate underlying causes only if hemoglobin is low or MCV is decreased, which would suggest functional iron deficiency despite adequate stores 1
The pattern of adequate ferritin with borderline TSAT does not represent pathology requiring intervention in this clinical context.