What is the treatment for low ferritin (iron deficiency)?

Treatment for Low Ferritin (Iron Deficiency)

Oral iron supplementation at 100-200 mg/day of elemental iron is the first-line treatment for low ferritin, with intravenous iron reserved for cases of oral intolerance, malabsorption, or need for rapid repletion. 1

Diagnostic Confirmation Before Treatment

• Confirm iron deficiency using serum ferritin as the most specific indicator of depleted iron stores 1
• Use a ferritin cutoff of 30 µg/L for adults over 15 years, though recent evidence suggests the physiologic cutoff may be closer to 50 ng/mL 1, 2
• Check C-reactive protein to exclude inflammation, which can falsely elevate ferritin levels and mask true iron deficiency 1, 3
• Iron supplementation should only be given when ferritin is low; supplementation with normal or high ferritin is potentially harmful 1

First-Line: Oral Iron Therapy

Dosing and Administration:

• Prescribe 100-200 mg/day of elemental iron in divided doses 1
• Standard ferrous sulfate tablets contain 324 mg ferrous sulfate, equivalent to 65 mg elemental iron 4
• Alternate-day dosing may improve absorption and reduce gastrointestinal side effects compared to daily dosing 1
• Treatment duration of at least 1 month is needed to correct anemia, with continued therapy to replenish iron stores 5

Enhancing Absorption:

• Co-administer vitamin C with iron supplements to enhance absorption 1
• Avoid tea and coffee around meal times as they impair iron absorption 1
• Counsel patients on incorporating heme iron (meat sources) and non-heme iron into their diet 3

Common Side Effects:

• Gastrointestinal symptoms including constipation, diarrhea, and nausea are common 1
• Using preparations with reasonable elemental iron content (28-50 mg) may reduce side effects and improve compliance 3

Second-Line: Intravenous Iron Therapy

Indications for IV Iron:

• Failure to reach therapeutic goal with oral supplementation 1
• Oral iron intolerance or gastrointestinal side effects 6
• Malabsorption conditions (celiac disease, post-bariatric surgery, inflammatory bowel disease) 1, 6
• Need for rapid iron repletion 1
• Active inflammatory bowel disease with hemoglobin below 100 g/L 1
• Chronic inflammatory conditions (chronic kidney disease, heart failure, cancer) 6
• Second and third trimesters of pregnancy 6
• Ongoing blood loss 6

IV Iron Administration:

• Give a single IV dose of 1 gram of whole-body iron replacement over 15 minutes using recent carbohydrate products 1
• Be aware that reactions during iron infusions may be life-threatening; risk minimization protocols should be followed 1

Monitoring and Follow-Up

• Repeat basic blood tests (hemoglobin, ferritin, mean cellular volume) after 8-10 weeks to assess treatment response 3
• For patients with recurrent low ferritin, provide intermittent oral supplementation and monitor every 6-12 months 3
• In high-risk populations (female athletes), monitor ferritin twice yearly 1

Critical Pitfalls to Avoid

• Do not miss inflammation-masked iron deficiency: Always check inflammatory markers, as inflammation falsely elevates ferritin 1, 3
• Do not ignore dietary factors: Failure to counsel on vitamin C enhancement and tea/coffee inhibition reduces treatment efficacy 1
• Do not continue iron supplementation with normal/high ferritin: This is potentially harmful and not recommended 1, 3
• Do not use excessive daily dosing: Consider alternate-day dosing to improve absorption and reduce side effects 1