Treatment of Iron Deficiency with Normal CBC
Start oral iron supplementation immediately at 100-200 mg elemental iron daily, as your laboratory findings confirm iron deficiency despite a normal CBC. 1, 2
Understanding Your Laboratory Results
Your iron studies demonstrate clear iron deficiency:
- Transferrin saturation of 10% is well below the diagnostic threshold of 15-20%, indicating insufficient iron available for red blood cell production 3, 1
- Ferritin of 10 ng/mL is significantly below the 30 ng/mL cutoff for iron deficiency in adults, confirming depleted iron stores 4, 2
- Normal CBC indicates you have iron deficiency without anemia (also called non-anemic iron deficiency), which still requires treatment 4, 2
This pattern affects approximately 38% of reproductive-age women and warrants treatment even before anemia develops. 2
First-Line Treatment: Oral Iron Therapy
Specific Dosing Recommendations
- Ferrous sulfate 325 mg daily (containing 65 mg elemental iron) is the standard first-line therapy 5, 6
- Alternative: 100-200 mg elemental iron daily in divided doses 1, 4
- Consider alternate-day dosing (every other day) as this improves iron absorption and reduces gastrointestinal side effects 2, 6
Optimizing Absorption
- Take on an empty stomach when possible for maximum absorption 1
- If gastrointestinal side effects occur, taking with food is acceptable despite reduced absorption 1
- Co-ingest with vitamin C to enhance absorption of non-heme iron 3
- Avoid tea and coffee around meal times as they impair iron absorption 3
Common Pitfalls to Avoid
Approximately 50% of patients experience decreased adherence due to adverse effects including constipation, diarrhea, and nausea. 1, 6 Using preparations with reasonable elemental iron content (28-50 mg) rather than excessive doses may improve tolerance. 4
Monitoring Response to Treatment
Initial Follow-Up Timeline
- Recheck hemoglobin at 2-4 weeks to assess early response 1, 6
- Complete iron panel at 8-10 weeks after starting therapy 1, 4
- Continue iron supplementation for a minimum of 8-10 weeks 1, 4
Expected Outcomes
Most patients with non-anemic iron deficiency experience improvement in symptoms such as fatigue, difficulty concentrating, irritability, and exercise intolerance with iron repletion. 2, 7
When to Consider Intravenous Iron
Intravenous iron should be considered if: 2, 6
- Oral iron is not tolerated despite dosing adjustments
- No adequate response after 2-4 weeks of oral therapy
- Malabsorption conditions are present (celiac disease, post-bariatric surgery, atrophic gastritis)
- Ongoing blood loss continues
- Chronic inflammatory conditions exist (though not mentioned in your case)
Hypersensitivity to newer intravenous iron formulations is rare (less than 1%). 6
Investigating Underlying Causes
While treating your iron deficiency, the underlying cause must be identified: 8, 2
In premenopausal women:
- Heavy menstrual bleeding is the most common cause and should be evaluated 8, 2
- If heavy menstrual bleeding is present and plausible as the sole cause, treatment of bleeding plus iron supplementation is reasonable 6
Additional evaluation needed:
- Test for Helicobacter pylori infection (common cause of iron deficiency) 6
- Test for celiac disease (impairs iron absorption) 6
- Consider dietary assessment, particularly if vegetarian/vegan diet 3, 4
- In men or postmenopausal women, bidirectional endoscopy is indicated as recurrent blood loss accounts for 94% of cases 6
Long-Term Management
If ferritin remains repeatedly low after initial treatment, you will benefit from: 4
- Intermittent oral iron supplementation to preserve iron stores
- Repeat iron studies every 6-12 months for monitoring
- Do not continue daily iron supplementation once ferritin normalizes, as this is potentially harmful 4