Treatment of Iron Deficiency with Normal Hemoglobin and Hematocrit
Start oral iron supplementation with ferrous sulfate 325 mg (65 mg elemental iron) twice daily and continue for 3 months after ferritin normalizes to replenish depleted iron stores, even though hemoglobin is currently normal. 1
Initial Treatment Approach
Oral iron therapy is the first-line treatment for iron deficiency without anemia. 1 The American Gastroenterological Association recommends ferrous sulfate 325 mg twice daily, providing 100-130 mg of elemental iron per day. 1 This approach is supported even when hemoglobin and hematocrit are normal, as the goal is to replenish depleted iron stores and prevent progression to anemia. 1
Dosing Strategies to Improve Tolerance
- Consider alternate-day dosing (every other day) rather than daily dosing, which may improve absorption and reduce gastrointestinal side effects while maintaining effectiveness. 1
- Lower doses may be equally effective: One tablet daily (65 mg elemental iron) can be as effective as higher doses and is better tolerated. 1
- Preparations containing 28-50 mg elemental iron are reasonable alternatives to prevent reduced compliance from gastrointestinal side effects. 2
Enhancing Iron Absorption
Add ascorbic acid (vitamin C) 250-500 mg twice daily with your iron supplement to enhance absorption. 1 This simple addition can significantly improve iron uptake from the gastrointestinal tract.
Critical Treatment Duration
The most common pitfall is stopping iron therapy too early. Continue iron supplementation for a full 3 months after ferritin normalizes (typically targeting ferritin 50-100 ng/mL) to adequately replenish iron stores. 1 Many patients discontinue therapy once they feel better or when hemoglobin normalizes, but this leaves iron stores depleted and leads to recurrence. 3
Monitoring Response to Treatment
- Recheck complete blood count and ferritin after 8-10 weeks of treatment to assess response. 1, 2
- Once ferritin normalizes, monitor every 3 months for the first year, then annually. 1
- If ferritin remains low after 8-10 weeks, consider investigating for ongoing blood loss, malabsorption, or non-adherence. 2
When Intravenous Iron Is NOT Indicated
Intravenous iron is not needed at this stage. 1 IV iron is reserved for specific situations:
- Intolerance to at least two different oral iron preparations 1
- Malabsorption conditions (celiac disease, inflammatory bowel disease, post-bariatric surgery) 4
- Hemoglobin <100 g/L (10 g/dL) 1
- Active inflammation compromising absorption 4
Investigating the Underlying Cause
Identify why iron stores are depleted, as this will guide long-term management. 1 Common causes include:
- Heavy menstrual bleeding (most common in premenopausal women) 4
- Dietary insufficiency (vegetarian/vegan diet, eating disorders) 2
- Occult gastrointestinal bleeding (requires investigation in men and postmenopausal women) 4, 5
- Malabsorption conditions: Consider testing for H. pylori and celiac disease if no obvious cause is identified and iron deficiency persists or recurs. 1
- Frequent blood donation 1
Investigation Algorithm Based on Patient Demographics
For premenopausal women <40 years without alarm symptoms: Bidirectional endoscopy (gastroscopy and colonoscopy) is not routinely required. 5 Focus on menstrual history and dietary assessment. 4
For men, postmenopausal women, or those with alarm symptoms: Perform bidirectional endoscopy to exclude gastrointestinal malignancy or other sources of blood loss. 4, 5 Upper gastrointestinal cancer occurs in 1/7 the frequency of colon cancer in this population. 5
Long-Term Management
- Patients with recurrent low ferritin benefit from intermittent oral supplementation to preserve iron stores. 2
- Long-term follow-up with basic blood tests every 6-12 months is appropriate for those at ongoing risk. 2
- Avoid long-term daily iron supplementation when ferritin is normal or high, as this is potentially harmful. 2