Is it concerning that a woman in her 60s requires ongoing iron supplementation to maintain normal ferritin levels?

Iron Supplementation in a 60-Year-Old Woman

It is concerning that a woman in her 60s requires ongoing iron supplementation to maintain normal ferritin levels, and she should undergo bidirectional endoscopy (upper and lower GI) to rule out gastrointestinal malignancy. 1, 2

Evaluation of Iron Deficiency in Older Adults

The American Gastroenterological Association (AGA) strongly recommends bidirectional endoscopy for asymptomatic postmenopausal women with iron deficiency anemia over no endoscopy 1. This recommendation is based on moderate quality evidence showing:

• Postmenopausal women have a significantly higher risk of gastrointestinal malignancy compared to premenopausal women
• The diagnostic yield of endoscopy is substantial in this population
• The potential benefits of detecting early malignancy outweigh the small risks of the procedure

Risk Assessment

For a woman in her 60s requiring ongoing iron supplementation:

• Gastrointestinal malignancy is a significant concern, particularly colorectal cancer
• Occult blood loss may be the underlying cause of persistent iron deficiency
• Even with normal ferritin levels while on supplementation, the underlying cause should be investigated 2

Diagnostic Approach

1. Confirm iron deficiency status:

   • Review ferritin levels (optimal cutoff is 45 ng/mL according to AGA guidelines) 1
   • Check transferrin saturation (TSAT) - values <20% suggest iron deficiency 2
   • Consider reticulocyte hemoglobin content (CHr) and soluble transferrin receptor (sTfR) for additional confirmation 2

2. Endoscopic evaluation:

   • Bidirectional endoscopy (colonoscopy and upper endoscopy) is strongly recommended 1
   • This should be performed even if iron supplementation is maintaining normal ferritin levels

3. Additional testing if endoscopy is negative:

   • Test for H. pylori and treat if positive 1
   • Consider celiac disease testing 1
   • Video capsule endoscopy may be considered if initial workup is negative 1

Management Considerations

While continuing diagnostic workup:

• Oral iron supplementation (ferrous sulfate 200 mg three times daily) is the first-line treatment 2
• Alternative formulations like ferrous gluconate or ferrous fumarate can be used if ferrous sulfate is not tolerated 2
• Iron therapy should continue for 3 months after hemoglobin normalization to replenish iron stores 2

Monitoring Response

• Hemoglobin should rise by approximately 2 g/dL after 3-4 weeks of treatment 2
• Failure to respond may indicate poor compliance, misdiagnosis, continued blood loss, or malabsorption 2
• Monitor ferritin levels every 6-12 months in high-risk patients 2

Important Caveats

• Do not assume menstrual blood loss: In a woman in her 60s, menstrual blood loss is no longer a plausible explanation for iron deficiency
• Do not delay endoscopy: Studies show that approximately 44% of patients with iron deficiency without obvious symptoms have an identifiable gastrointestinal lesion, including 21% with colonic carcinoma 3
• Avoid unnecessary supplementation: Iron supplementation in patients with normal or high ferritin is not recommended and potentially harmful 2
• Consider medication interactions: Oral iron products interfere with absorption of tetracycline antibiotics and should not be taken within two hours of each other 4

The need for ongoing iron supplementation in a postmenopausal woman should always trigger a thorough gastrointestinal evaluation, as this could be the only sign of an underlying gastrointestinal malignancy or chronic blood loss.