Serum Ferritin Level
Serum Ferritin Levels
Introduction
- Primary biomarker for iron storage evaluation in pediatric populations
- Acute phase reactant protein that reflects total body iron stores
- Essential for screening, diagnosis, and monitoring of iron deficiency states
Key Physiological Points
- Synthesized by hepatocytes and reticuloendothelial cells
- Each ferritin molecule can store up to 4500 iron atoms
- Levels vary significantly with age, gender, and developmental stage
Clinical Significance
Indications for Testing
- Suspected iron deficiency anemia
- Chronic disease evaluation
- Growth and development monitoring
- Inflammatory conditions assessment
- Hereditary hemochromatosis screening
Advantages
- High sensitivity for iron deficiency
- Earlier detection than hemoglobin changes
- Reflects iron stores more accurately than serum iron
- Minimal diurnal variation
Interpretation Guidelines
Reference Ranges
Newborns (cord blood)
60-400 ng/mL
1 month
200-600 ng/mL
2-5 months
50-200 ng/mL
6 months-15 years
15-120 ng/mL
Critical Values
- Severe deficiency: <12 ng/mL
- Mild-moderate deficiency: 12-30 ng/mL
- Iron overload: >300 ng/mL
Age-Specific Considerations
Neonatal Period
- Higher values due to maternal transfer
- Gradual decline over first 2 months
- Influenced by gestational age and birth weight
Infancy (0-12 months)
- Critical period for iron store development
- Affected by feeding type (breast vs. formula)
- Regular monitoring recommended
Early Childhood
- Stabilization of values
- Dietary factors become crucial
- Growth spurts may affect levels
Clinical Correlation
Common Causes of Low Ferritin
- Iron deficiency anemia
- Malnutrition
- Malabsorption disorders
- Chronic blood loss
Common Causes of High Ferritin
- Acute inflammation
- Chronic disease
- Hemochromatosis
- Malignancy
- Liver disease
Diagnostic Pearls
- Consider concurrent CRP testing in inflammatory conditions
- Serial measurements more valuable than single readings
- Interpret in context of complete blood count
- Account for recent iron supplementation
