Management of Iron Deficiency Without Anemia
Your laboratory values indicate iron deficiency without anemia, and you should initiate oral iron supplementation at 100-200 mg elemental iron daily while investigating the underlying cause of iron loss. 1
Laboratory Interpretation
Your results demonstrate a clear pattern of iron deficiency:
- RBC count (5.69) and hematocrit (46.1%) are normal, indicating you do not have anemia 2
- MCH of 26.7 pg is low (normal range typically 27-33 pg), indicating hypochromia and iron deficiency 1
- Elevated transferrin (365 mg/dL) and TIBC (511 mg/dL) are classic markers of iron deficiency, as your body increases iron-binding capacity to compensate for low iron availability 1, 2
- The elevated TIBC strongly supports iron deficiency, as TIBC increases when serum iron concentration and stored iron are low 2
This represents non-anemic iron deficiency, a condition where iron stores are depleted but hemoglobin remains within normal range 1. This stage precedes the development of frank iron deficiency anemia if left untreated.
Essential Additional Testing Required
You need a complete iron panel to confirm the diagnosis and guide treatment:
- Serum ferritin (most important): Values <30 μg/L confirm iron deficiency in the absence of inflammation 1, 2
- Transferrin saturation (TSAT): Calculate from serum iron ÷ TIBC × 100; values <16-20% confirm iron deficiency 1, 2
- Serum iron: Expected to be low in iron deficiency 1, 2
- C-reactive protein (CRP): To assess for inflammation, which can falsely elevate ferritin 2
Treatment Recommendations
Oral Iron Supplementation
Start oral iron at 100-200 mg elemental iron daily in divided doses 1. Recent evidence suggests alternate-day dosing may improve absorption with fewer side effects 1.
- Common side effects include constipation, diarrhea, and nausea 1
- Recheck hemoglobin and iron studies after 8-10 weeks, not earlier, as ferritin levels can be falsely elevated immediately after supplementation 1
- Expect a hemoglobin increase of 1-2 g/dL within one month if treatment is effective 3
When to Consider Intravenous Iron
IV iron is reserved for specific situations 1:
- Failure to respond to oral iron after 8-10 weeks
- Gastrointestinal intolerance to oral iron
- Malabsorption conditions
- Need for rapid iron repletion (e.g., before elective surgery)
Investigating the Underlying Cause
Iron deficiency rarely occurs without an identifiable source 2. You must investigate:
Common Causes to Evaluate:
- Gastrointestinal blood loss: Most common in men and postmenopausal women; may require endoscopic evaluation 3
- Menstrual blood loss: Primary cause in premenopausal women 2
- Dietary insufficiency: Restrictive diets, vegetarian/vegan diets 2
- Malabsorption: Celiac disease, inflammatory bowel disease, H. pylori infection 4
- Medications: NSAIDs causing occult GI bleeding 2
- Blood donation or high-impact athletic activity causing hemolysis 2
Age and Gender-Specific Approach:
- Men and postmenopausal women: GI evaluation is often warranted, starting with colonoscopy if over age 50 3
- Premenopausal women: If menstrual history and dietary assessment are unrevealing, consider GI evaluation 3
Critical Pitfalls to Avoid
- Do not assume normal RBC and hematocrit exclude iron deficiency: Many cases are missed when only CBC is ordered without iron studies 5
- Do not supplement iron if ferritin is normal or elevated without confirming true deficiency: Iron supplementation with normal/high ferritin is potentially harmful 1
- Do not ignore inflammation: Ferritin is an acute-phase reactant and can be falsely normal or elevated during inflammation, masking true iron deficiency 1, 2
- In inflammatory states, ferritin up to 100 μg/L may still indicate iron deficiency 2