What is the management plan for a 47-year-old female with a low ferritin level (Hypoferritinemia) of 8?

Management of Ferritin 8 ng/mL in a 47-Year-Old Female

This 47-year-old woman has confirmed iron deficiency (ferritin 8 ng/mL is well below the diagnostic threshold of <15 ng/mL) and requires immediate iron supplementation along with investigation for the underlying cause of iron depletion. 1

Immediate Diagnostic Confirmation

• Check complete blood count (CBC) to determine if anemia is present (hemoglobin <12 g/dL in women) 1
• A ferritin ≤15 μg/L confirms depleted iron stores with 98% specificity in women of childbearing age 1
• Measure transferrin saturation if available, as a TSAT <20% has high sensitivity for diagnosing absolute iron deficiency 1
• Since this patient has a ferritin of 8 ng/mL, she definitively has iron deficiency regardless of whether anemia is present 1, 2

Investigation for Underlying Cause

All women with iron deficiency require evaluation for the source of iron loss, even premenopausal women: 1

• Detailed menstrual history: Quantify menstrual blood loss (though history alone is unreliable; pictorial blood loss assessment charts have ~80% sensitivity/specificity for menorrhagia) 1
• Gastrointestinal evaluation: Upper endoscopy with small bowel biopsy and colonoscopy are indicated, as significant GI pathology can occur even in menstruating women 1
• Dietary assessment: Evaluate for inadequate iron intake, vegetarian/vegan diet, or malabsorption conditions 1, 3
• Screen for celiac disease with serologic testing, as this commonly causes iron malabsorption 1
• Check for H. pylori infection, which can impair iron absorption 1
• Assess medication use: NSAIDs can cause occult GI bleeding 1

Iron Replacement Strategy

First-Line: Oral Iron Supplementation

Start oral ferrous sulfate 200 mg three times daily (or equivalent formulation providing 28-50 mg elemental iron per dose): 1, 4, 3

• Ferrous sulfate, ferrous gluconate, and ferrous fumarate are equally effective 1
• Take on an empty stomach when possible for optimal absorption; if not tolerated, take with meals (preferably with meat protein) 1
• Co-administer with 500 mg vitamin C to enhance absorption, especially when taken with food 1
• Avoid tea, coffee, and calcium supplements around dosing times as they inhibit iron absorption 1

Continue oral iron for 3 months after hemoglobin normalizes to replenish iron stores 1

When to Consider Intravenous Iron

IV iron should be considered if: 1

• Intolerance to at least two different oral iron preparations
• Malabsorption conditions (celiac disease, inflammatory bowel disease, post-bariatric surgery)
• Severe symptomatic iron deficiency requiring rapid repletion
• Failure to respond to adequate oral iron therapy after 4-8 weeks

Available IV formulations include: iron sucrose, ferric carboxymaltose, low molecular weight iron dextran, and ferric derisomaltose, with total dose infusions of 1000-1500 mg possible 1

Monitoring Response to Treatment

Recheck labs 4-8 weeks after starting iron therapy: 1

• Hemoglobin should increase by 1-2 g/dL within 4-8 weeks 1
• Target ferritin goal is ≥50 ng/mL in the absence of inflammation 1
• Do not check iron parameters within 4 weeks of IV iron administration, as circulating iron interferes with assays 1

After initial correction, monitor every 3 months for the first year, then annually: 1

• If ferritin or hemoglobin falls below normal, resume oral iron supplementation 1
• Repeat ferritin measurement is indicated if symptoms recur 1

Critical Pitfalls to Avoid

Do not assume menstruation alone explains iron deficiency in women over 45 years old - the incidence of GI pathology increases significantly with age, and this patient warrants full GI evaluation 1

Do not give IV iron without first checking ferritin - iron overload can occur with inappropriate supplementation, particularly in rare genetic conditions causing hypoferritinemia 5

Do not use ferritin alone if inflammation is suspected - ferritin is an acute phase reactant and can be falsely elevated; check C-reactive protein and consider transferrin saturation or soluble transferrin receptor if ferritin is 15-100 ng/mL with suspected iron deficiency 1, 3

Avoid excessive vitamin C supplementation (limit to 500 mg/day) as higher doses may be harmful in iron-deficient states 1

Special Considerations for This Patient

At age 47, this patient is likely perimenopausal but still menstruating. The combination of low ferritin (8 ng/mL) and her age mandates GI investigation regardless of menstrual history, as colorectal cancer and other significant pathology become more prevalent in this age group 1

If she has symptoms of fatigue with this degree of iron deficiency (ferritin <50 μg/L), iron supplementation will likely provide significant symptomatic benefit even if she is not anemic 6