What is the recommended treatment for low ferritin (iron) levels in a young female?

Treatment of Low Ferritin in Young Females

Young women with low ferritin should receive oral iron supplementation at 60-120 mg elemental iron on alternate days, taken in the morning with vitamin C, for 8-12 weeks, even if hemoglobin is normal. 1

Diagnostic Thresholds and Clinical Significance

• Ferritin <15 μg/L has 99% specificity for absolute iron deficiency and confirms the diagnosis definitively 1, 2
• Ferritin <35 μg/L indicates depleted iron stores and warrants treatment, even without anemia 1
• Iron deficiency without anemia still causes significant symptoms including fatigue, lethargy, and reduced exercise tolerance 1, 2
• Young menstruating women are at highest risk, with average ferritin levels of only 43 μg/L compared to 135 μg/L in men, due to menstrual blood loss averaging 0.3-0.5 mg iron daily 2, 3

First-Line Treatment: Oral Iron Supplementation

Optimal Dosing Regimen

The most effective oral iron regimen is 60-120 mg elemental iron given on alternate days in the morning, rather than daily divided doses. 4 This approach is based on recent evidence showing:

• Oral iron doses ≥60 mg stimulate an acute hepcidin increase that persists 24 hours but subsides by 48 hours 4
• Alternate-day dosing maximizes fractional iron absorption by allowing hepcidin to return to baseline 4
• Morning dosing is superior because the circadian hepcidin increase is augmented by morning iron doses, making afternoon/evening doses less effective 4
• Lower doses result in smaller hepcidin increases and potentially more efficient absorption 5

Specific Iron Formulations

Choose from these FDA-approved oral iron preparations 6, 7, 8:

• Ferrous sulfate 324 mg (provides 65 mg elemental iron per tablet) 6
• Ferrous gluconate 324 mg (provides 38 mg elemental iron per tablet) 7
• Ferrous fumarate 325 mg (provides approximately 106 mg elemental iron per tablet) 8

Slow-release ferrous sulfate formulations are recommended as the most effective and tolerable supplement. 1

Duration and Co-Administration

• Continue supplementation for 8-12 weeks to replenish iron stores 1
• Co-administer with 250-500 mg vitamin C to enhance absorption 1
• Avoid tea and coffee around dosing times as they impair iron absorption 1

Dietary Optimization

While awaiting or alongside supplementation:

• Increase dietary iron intake to at least 18-22 mg/day (the RDA is 18 mg/day for women 19-50 years, but active women may need 22 mg/day) 1
• Prioritize heme iron sources (red meat, seafood) which have substantially higher bioavailability than plant-based non-heme iron 1
• For vegetarians/vegans, consume non-heme iron with vitamin C to enhance absorption 1

When to Consider Parenteral Iron

Intravenous iron is reserved for special circumstances 1:

• Severe iron deficiency with ferritin <12 μg/L and hemoglobin <11.5 g/dL 1
• Documented malabsorption (e.g., celiac disease, inflammatory bowel disease) 1
• Intolerance to oral iron despite formulation changes 1
• Failure to respond to adequate oral supplementation 1

Intravenous iron preparations include: 1

• Iron sucrose (Venofer): 200 mg over 10 minutes
• Ferric carboxymaltose (Ferinject): up to 1000 mg over 15 minutes
• Iron dextran (Cosmofer): up to 20 mg/kg over 6 hours (carries 0.6-0.7% risk of serious reactions)

Mandatory Investigations

All young women with low ferritin must be screened for celiac disease with tissue transglutaminase antibodies (tTG Ab), as celiac disease is present in up to 4% of premenopausal women with iron deficiency 1

Additional investigations for women ≥50 years or with concerning symptoms 1:

• Upper GI endoscopy if upper GI symptoms present
• Colonoscopy if strong family history of colorectal cancer or persistent deficiency despite treatment
• Assessment for heavy menstrual bleeding (>80 mL/month affects 10% of women) 3

Monitoring and Follow-Up

• Recheck ferritin at 3 months after starting supplementation to confirm response 1
• For menstruating females at high risk, screen twice yearly for iron deficiency 1
• Once normalized, monitor at 3-month intervals for 1 year, then annually 1
• Target ferritin level should be at least 35-50 μg/L to ensure adequate stores 1, 2

Critical Caveats

• Rule out inflammation before interpreting ferritin: Ferritin is an acute-phase reactant that rises with infection, inflammation, or tissue damage, potentially masking true iron deficiency 2, 3
• If inflammatory markers (CRP/ESR) are elevated, use transferrin saturation <16% as an additional marker of iron deficiency 1, 2
• High-dose daily iron (≥100 mg/day) may increase lipid peroxidation and cause gastrointestinal side effects, reducing compliance 4, 9
• Unabsorbed iron can cause gut irritation, inflammation, and dysbiosis 4