Primary Causes of Low Ferritin in Children
The most common cause of low ferritin in children is inadequate dietary iron intake, which is especially prevalent in children aged 9-18 months due to their rapid growth rate and frequently insufficient iron consumption. 1
Understanding Iron Deficiency in Children
Iron deficiency represents a spectrum ranging from iron depletion (reduced iron stores) to iron-deficient erythropoiesis (depleted stores affecting red blood cell production) to iron-deficiency anemia (the most severe form). Serum ferritin is the most specific indicator available for depleted iron stores and an early marker of iron deficiency. 1
Risk Factors and High-Risk Populations
Children at highest risk for low ferritin levels include:
- Infants and toddlers aged 9-18 months (highest risk group) 1, 2
- Preterm and low-birthweight infants (depleted iron stores by 2-3 months of age) 1
- Children living at or below poverty level 1
- Children with poor dietary iron intake 3
Major Causes of Low Ferritin in Children
1. Inadequate Dietary Iron Intake
- Most common cause globally and in developed countries 2, 3
- Critical during periods of rapid growth (6-24 months) 1
- Particularly problematic when:
- Transitioning from breast milk/formula to solid foods without adequate iron-rich foods
- Excessive consumption of cow's milk (which is low in iron and can cause occult intestinal bleeding) 1
2. Increased Iron Requirements
- Rapid growth periods (infancy and adolescence) 2
- Preterm infants have lower iron stores at birth 1
- Catch-up growth in previously malnourished children
3. Blood Loss
- Gastrointestinal blood loss:
- Menstrual blood loss in adolescent females 5
4. Impaired Iron Absorption
- Celiac disease 3
- Inflammatory bowel disorders
- Atrophic gastritis
- Post-bariatric surgery (rare in children) 5
5. Chronic Inflammatory Conditions
- Chronic infections
- Autoimmune disorders
- Note: Inflammation can artificially elevate ferritin levels, potentially masking iron deficiency 1
Diagnostic Considerations
When evaluating low ferritin in children, consider that:
- Serum ferritin <20 μg/L in children aged 12-59 months indicates iron deficiency based on physiological evidence 6
- Ferritin is an acute-phase reactant; inflammation, infection, or tissue damage can raise ferritin levels independent of iron status, potentially masking iron deficiency 1
- Multiple measurements may be needed due to day-to-day variations 1
Clinical Implications
Iron deficiency in children, even without anemia, can have significant consequences:
- Developmental delays and behavioral disturbances 1
- Decreased motor activity, social interaction, and attention 1
- Developmental delays may persist beyond school age if iron deficiency is not fully reversed 1
- Increased susceptibility to lead poisoning due to enhanced gastrointestinal absorption of heavy metals 1
Prevention Approach
Primary prevention of iron deficiency is crucial for children under 2 years:
- Ensure adequate iron intake through diet or supplements
- Breastfed infants may need iron supplementation after 4-6 months
- Limit cow's milk consumption in young children
- Screen high-risk children for iron deficiency
Early identification and treatment of low ferritin levels is essential to prevent the progression to iron deficiency anemia and its associated developmental consequences.