Management of Iron Deficiency in an 11-Year-Old Female with Ferritin 16 ng/mL
Start oral iron supplementation immediately with ferrous sulfate 200 mg three times daily and continue for three months after hemoglobin normalizes to replenish iron stores. 1, 2
Confirm the Diagnosis
- A ferritin of 16 ng/mL confirms iron deficiency, as levels below 15-20 ng/mL in adolescents aged 12-15 years indicate depleted iron stores 3
- Check hemoglobin, MCV, and MCH to assess for anemia and characterize the deficiency 2
- Exclude inflammatory conditions by checking C-reactive protein, as inflammation can falsely elevate ferritin levels 3
Initiate Oral Iron Therapy
- Ferrous sulfate 200 mg three times daily is the first-line treatment 1, 2
- Alternative preparations include ferrous gluconate or ferrous fumarate if ferrous sulfate is not tolerated 1
- Liquid preparations may be better tolerated than tablets in some adolescents 1
- Administer iron on an empty stomach when possible to maximize absorption 2
Enhance Iron Absorption
- Add vitamin C 500 mg with iron supplements to enhance absorption, particularly if initial response is poor 1, 2
- Counsel on dietary iron intake: encourage heme iron sources (meat, poultry, fish) and plant-based iron with vitamin C-rich foods 4
- Avoid calcium supplements, tea, coffee, and dairy products within 2 hours of iron administration, as these inhibit absorption 4
Identify and Address the Underlying Cause
- In an 11-year-old female approaching menarche or with established menstruation, menstrual blood loss is the most likely cause 1
- Assess dietary habits: vegetarian/vegan diets, eating disorders, and inadequate dietary iron intake are common risk factors in adolescents 4, 5
- Limit cow's milk intake to no more than 24 oz daily, as excessive milk consumption impairs iron absorption 1
- Screen for celiac disease if there are gastrointestinal symptoms or poor response to therapy 1
Monitor Treatment Response
- Hemoglobin should rise by 2 g/dL after 3-4 weeks of therapy 1
- Recheck hemoglobin, MCV, and ferritin after 8-10 weeks to assess response 3
- Continue oral iron for three months after hemoglobin normalizes to adequately replenish iron stores 1, 2
Follow-Up Strategy
- Monitor hemoglobin and red cell indices every 3 months for one year, then annually 1, 2
- Restart oral iron if hemoglobin or MCV falls below normal during follow-up 1
- Consider intermittent oral iron supplementation in adolescents with recurrent deficiency to maintain stores 3
When Oral Iron Fails
- Consider intravenous iron only if there is intolerance to at least two different oral iron preparations, non-compliance, or failure to respond after adequate oral therapy 1, 2
- Failure to respond to oral iron is usually due to poor compliance, continued blood loss, malabsorption, or misdiagnosis 1
- Parenteral iron carries risks of anaphylaxis and does not increase hemoglobin faster than oral preparations 1
Common Pitfalls to Avoid
- Do not administer iron more than once daily, as this reduces absorption efficiency 4
- Avoid long-term iron supplementation once ferritin normalizes, as this is potentially harmful 3
- Do not overlook gastrointestinal side effects, which are the main cause of non-compliance; consider alternate-day dosing or lower-dose preparations (28-50 mg elemental iron) if side effects occur 3