Treatment of Low Ferritin Levels
For patients with low ferritin levels, oral ferrous sulfate 200 mg three times daily is the first-line treatment, continued for three months after hemoglobin normalizes to fully replenish iron stores. 1, 2
Initial Treatment Approach
Oral Iron Supplementation (First-Line)
- Start with ferrous sulfate 200 mg (containing 65 mg elemental iron) three times daily as the most cost-effective option 1, 2, 3
- Alternative oral formulations include ferrous gluconate or ferrous fumarate, which are equally effective if ferrous sulfate is not tolerated 1, 2, 4
- Liquid preparations may be better tolerated when tablets cause gastrointestinal side effects 1
Enhancing Absorption
- Add ascorbic acid (vitamin C) to enhance iron absorption, particularly when response is poor 1, 2
- Vitamin C should be co-ingested with non-heme iron sources 5
- Avoid tea and coffee around meal times as they impair iron absorption 5
Treatment Duration and Monitoring
Duration of Therapy
- Continue iron supplementation for three months after hemoglobin levels normalize to ensure adequate replenishment of iron stores 1, 2
- Discontinuing therapy prematurely leads to recurrence of iron deficiency, as body stores may remain depleted even when hemoglobin has normalized 1
Monitoring Schedule
- Monitor hemoglobin and red cell indices (MCV) every three months for one year, then annually 1, 2
- Expect hemoglobin to rise by 2 g/dL after 3-4 weeks of treatment 2
- Check ferritin levels if hemoglobin or MCV falls below normal during follow-up 1, 2
- Repeat basic blood tests after 8-10 weeks to measure treatment success 5, 6
When to Escalate to Intravenous Iron
Reserve parenteral iron for specific scenarios only:
- Intolerance to at least two different oral iron preparations 1, 2
- Non-compliance with oral therapy 1, 2
- Patients requiring rapid iron replacement (e.g., before elective surgery) 5
- Repeated failure of first-step oral therapy 6
Intravenous Iron Administration
- Ferric carboxymaltose allows administration of up to 1000 mg of iron over 15 minutes 5, 7
- IV iron is associated with rapid increases in hemoglobin and ferritin levels 7
- Risk of serious reactions is very low (<1:250,000 administrations with recent formulations) but may be life-threatening 5
Addressing Underlying Causes
Critical Consideration for Women with Menstrual Blood Loss
- Treating iron deficiency alone without addressing heavy menstrual bleeding will result in treatment failure 2
- Consider tranexamic acid or hormonal therapy to reduce menstrual blood loss 8
- Women over 45 years with iron deficiency require gastrointestinal evaluation even when menstrual blood loss is present 2
For Gastrointestinal Causes
- Investigate and treat underlying gastrointestinal disorders causing blood loss 9
- Exclude malabsorption conditions (e.g., celiac disease) if oral iron is ineffective 5
Dietary Recommendations
- Integrate heme iron (from red meat and seafood) regularly into the diet, as it has substantially higher bioavailability than non-heme iron 5, 6
- This is particularly important for vegetarians and vegans, who are at higher risk for iron deficiency 5
- Dietary modifications alone should not substitute for iron supplementation when deficiency is present 6
Important Caveats and Pitfalls
Avoid Overtreatment
- Iron supplementation in the presence of normal or high ferritin values is not recommended and is potentially harmful 5, 6
- Always exclude inflammation before interpreting ferritin levels, as ferritin is an acute phase reactant and may be falsely elevated 5, 6
- Measure C-reactive protein to exclude acute phase reaction 6
Common Causes of Treatment Failure
- Poor compliance is the most common cause of treatment failure, often due to gastrointestinal side effects 2
- Continued blood loss exceeding iron replacement 2
- Malabsorption or misdiagnosis 2
- Using preparations with excessive elemental iron content (>50 mg) may reduce compliance due to side effects 6