What is the treatment for a patient with hypoferritinemia (low iron level of 25) and low percent saturation of 8?

Treatment of Iron Deficiency with Low Iron Level (25) and Low Transferrin Saturation (8%)

You need to start iron supplementation immediately, and the choice between oral versus intravenous iron depends on whether you have anemia, the severity of symptoms, and whether there's underlying inflammation or malabsorption. 1

Diagnostic Confirmation

Your laboratory values confirm absolute iron deficiency:

• Transferrin saturation of 8% is well below the diagnostic threshold of 16% used to define iron deficiency in non-inflammatory states 1
• A serum iron level of 25 (assuming ng/mL for ferritin) is consistent with depleted iron stores 1
• These values indicate you need treatment regardless of whether you have anemia yet 1, 2

Investigation Before Treatment

Before starting iron therapy, you must identify the underlying cause of iron deficiency to prevent recurrence and rule out serious pathology: 1

• If you are a man or postmenopausal woman: Gastrointestinal evaluation with bidirectional endoscopy (both upper and lower) is mandatory to exclude GI malignancy, even without anemia 1
• If you are a premenopausal woman: Assess for menstrual blood loss first; GI investigation is generally not warranted unless there are additional concerning symptoms or the iron deficiency persists despite treatment 1
• Screen for celiac disease with tissue transglutaminase (tTG) antibody testing, as this affects up to 5% of patients with iron deficiency and will impact treatment success 1
• Review medications: Stop NSAIDs and aspirin if clinically feasible, as these are common causes of occult GI blood loss 1

Treatment Algorithm

First-Line: Oral Iron Supplementation

Start with oral ferrous sulfate 324 mg (65 mg elemental iron) once daily or every other day: 3, 2

• Dosing strategy: Recent evidence suggests alternate-day dosing (every other day) may improve absorption and reduce side effects compared to daily dosing 1
• Take on an empty stomach when possible for optimal absorption, or with meals if gastrointestinal side effects occur 1
• Enhance absorption by taking with 500 mg vitamin C or with meat protein 1
• Avoid inhibitors: Do not take with calcium supplements, antacids, or high-fiber meals 1
• Expected response: Hemoglobin should increase by 10-20 g/L (1-2 g/dL) within 2-4 weeks if treatment is effective 1, 4

When to Use Intravenous Iron Instead

Switch to IV iron if any of the following apply: 1, 2

• Failure of oral iron: No hemoglobin response after 4-6 weeks of adequate oral supplementation 2, 5
• Intolerance to oral iron: Gastrointestinal side effects (nausea, constipation, abdominal pain) preventing compliance 1
• Malabsorption conditions: Confirmed celiac disease, inflammatory bowel disease, or prior gastric surgery 1
• Severe anemia requiring rapid correction: Hemoglobin <100 g/L with symptoms 1
• Ongoing blood losses that exceed oral replacement capacity 1, 6

IV Iron Administration

Ferric carboxymaltose is the preferred formulation as it allows single large-dose infusions (up to 1000 mg elemental iron) over 15 minutes with minimal risk of reactions 1

• Alternatives include: Iron sucrose, ferric gluconate, or low molecular weight iron dextran 1
• Avoid high molecular weight iron dextran due to higher risk of anaphylaxis 1
• Test dose: A 25 mg test dose is recommended before full-dose iron dextran administration 1

Monitoring Treatment Response

Recheck complete blood count and iron studies 8-10 weeks after starting treatment: 1, 2

• Do not check ferritin earlier than 8 weeks after IV iron, as levels will be falsely elevated 1
• Target iron parameters: Transferrin saturation >20% and ferritin >30 μg/L (or >100 μg/L if inflammatory condition present) 1
• If no response to oral iron: Consider malabsorption, ongoing blood loss, or incorrect diagnosis 1, 4

Special Considerations for Inflammation

If you have an inflammatory condition (elevated CRP, active IBD, chronic kidney disease):

• Higher ferritin thresholds apply: Iron deficiency is likely even with ferritin 30-100 μg/L when transferrin saturation is <16% 1
• Ferritin >100 μg/L with transferrin saturation <16% suggests anemia of chronic disease rather than pure iron deficiency 1
• IV iron is more effective than oral iron in inflammatory states due to hepcidin-mediated blockade of intestinal iron absorption 1

Long-Term Management

After iron repletion, assess need for maintenance therapy: 2

• Intermittent oral iron supplementation (e.g., weekly or monthly) may be needed if the underlying cause cannot be corrected 2
• Repeat iron studies every 6-12 months in patients at risk for recurrent deficiency 2
• Do not continue iron supplementation if ferritin normalizes without ongoing losses, as excess iron is potentially harmful 1, 2

Critical Pitfall to Avoid

Never assume dietary insufficiency alone in men or postmenopausal women—GI pathology including malignancy must be excluded first, as up to 9% of patients over 65 with iron deficiency have GI cancer 1, 4