In a child with ferritin 100 ng/mL, serum iron 2.6 µmol/L, and total iron‑binding capacity 65.8 µmol/L, how should the anemia be managed?

Management of Iron Deficiency in This Child

This child has iron deficiency anemia and should be started on oral ferrous sulfate 3-6 mg/kg/day of elemental iron, given daily or on alternate days, with reassessment in 4-8 weeks to confirm hemoglobin rise of 1-2 g/dL.

Interpretation of Laboratory Values

Your child's labs reveal clear iron deficiency:

• Ferritin 100 ng/mL: While this appears "normal," in the context of the low serum iron and TIBC, this suggests either early iron deficiency or iron deficiency with concurrent inflammation (ferritin is an acute phase reactant) 1
• Serum iron 2.6 µmol/L (approximately 14.5 µg/dL): This is low
• TIBC 65.8 µmol/L (approximately 368 µg/dL): This is elevated, indicating the body is trying to capture more iron
• Calculated transferrin saturation (TSAT): Approximately 4% - severely low (normal >20%)

A TSAT <20% has high sensitivity for diagnosing absolute or functional iron deficiency 1. Your child's TSAT of ~4% confirms significant iron deficiency despite the ferritin of 100 ng/mL.

First-Line Treatment: Oral Iron

Start oral ferrous sulfate immediately 2, 3:

• Dose: 3-6 mg/kg/day of elemental iron (ferrous sulfate 325 mg contains 65 mg elemental iron)
• Frequency: Daily dosing OR alternate-day dosing (both are effective, alternate-day may improve absorption and reduce side effects) 1
• Timing: Give on empty stomach if tolerated; with food if gastrointestinal side effects occur
• Duration: Continue for 3 months after hemoglobin normalizes to replenish iron stores 2

Ferrous sulfate is superior to other iron compounds (including iron polymaltose complex) in raising hemoglobin levels 3, though it does cause more gastrointestinal side effects.

Monitoring Response

Check complete blood count and iron parameters 4-8 weeks after starting treatment 1:

• Expected response: Hemoglobin should increase by 1-2 g/dL within 4-8 weeks
• Reticulocyte count: Should rise within 1-2 weeks (indicates bone marrow response)
• If inadequate response: Consider non-compliance, ongoing blood loss, malabsorption, or incorrect diagnosis

Investigate the Underlying Cause

Critical step: Identify why this child is iron deficient 2, 4:

• Dietary history: Inadequate iron intake, excessive cow's milk consumption (>24 oz/day in young children)
• Growth velocity: Rapid growth increases iron requirements
• Blood loss: Gastrointestinal (Meckel's diverticulum, polyps, inflammatory bowel disease), menstrual (in adolescent girls), parasitic infections
• Malabsorption: Celiac disease, inflammatory bowel disease, Helicobacter pylori
• Birth history: Low birth weight, prematurity

When to Consider Intravenous Iron

Switch to IV iron if 1, 4:

• Oral iron fails after 4-8 weeks of adequate therapy
• Intolerance to oral iron (severe gastrointestinal side effects)
• Malabsorption documented (celiac disease, inflammatory bowel disease)
• Ongoing significant blood loss that cannot be controlled
• Chronic inflammatory conditions (though less common in children)

Common Pitfalls to Avoid

• Don't recheck iron parameters within 4 weeks of starting treatment - circulating iron interferes with assays and gives spurious results 1
• Don't stop iron when hemoglobin normalizes - continue for 3 months to replenish stores 2
• Don't ignore the elevated TIBC and low TSAT just because ferritin is 100 ng/mL - the discordance indicates true iron deficiency 1
• Don't forget to investigate the cause - if dietary insufficiency is excluded and oral iron fails, blood loss must be considered, especially in older children 2

Nutritional Counseling

Educate the family on 2:

• Iron-rich foods: Red meat, poultry, fish, beans, fortified cereals
• Enhance absorption: Vitamin C-rich foods with iron
• Avoid inhibitors: Limit cow's milk, tea, calcium supplements around iron dosing
• Limit cow's milk: Maximum 16-24 oz/day in young children