What is the best approach to manage potential iron deficiency anemia in a woman of childbearing age with hemoglobin 13.5, normal B12, iron 53, TIBC 211, iron saturation 25, and ferritin 31.9?

Management of Low Iron Stores in a Woman of Childbearing Age

This patient has depleted iron stores (ferritin 31.9 μg/L) without anemia and should receive oral iron supplementation while investigating for underlying causes of iron loss, particularly menstrual blood loss. 1, 2

Interpretation of Laboratory Values

Your patient's results indicate non-anemic iron deficiency (NAID):

• Hemoglobin 13.5 g/dL: Above the anemic threshold for women (WHO defines anemia as <12.0 g/dL in non-pregnant women) 1, 2
• Ferritin 31.9 μg/L: Indicates depleted iron stores, as values <30 μg/L confirm iron deficiency with 93% specificity in women of childbearing age, and your patient falls just above this threshold 2
• Transferrin saturation 25%: Normal (>20% excludes iron deficiency in most cases), though this can be falsely reassuring 1, 3
• Iron 53 and TIBC 211: Consistent with early iron depletion 1

The British Society of Gastroenterology notes that ferritin levels <45 μg/L warrant consideration of investigation, especially with a chronic inflammatory process, though your patient's ferritin of 31.9 μg/L clearly indicates low body iron stores even without inflammation 1

Clinical Approach

Identify the Underlying Cause

In premenopausal women with NAID, menstrual blood loss is the most likely etiology and gastrointestinal investigation is generally not warranted in the absence of other concerning features. 1, 3

Specifically assess for:

• Heavy menstrual bleeding (menorrhagia affects 10% of women of childbearing age and is the leading cause of iron deficiency in this population) 1, 3
• Dietary inadequacy (most women have iron intake below recommended levels) 1
• Gastrointestinal symptoms (abdominal pain, change in bowel habits, blood in stool) that would prompt endoscopic evaluation 1
• Medications (NSAIDs, aspirin, anticoagulants that increase bleeding risk) 3
• Malabsorption symptoms (screen for celiac disease if diarrhea, weight loss, or bloating present) 1, 3

The British Society of Gastroenterology states that the overall prevalence of significant GI pathology, particularly malignancy, is low in NAID among premenopausal women, and GI investigation generally is not warranted without additional clinical pointers 1

Treatment Strategy

Initiate oral iron supplementation:

• Ferrous sulfate 325 mg daily or on alternate days is first-line therapy 3
• Dosing of 3-6 mg/kg elemental iron per day achieves optimal response 4
• Alternate-day dosing may improve tolerability with similar efficacy 3

Monitor response at 2-4 weeks:

• A hemoglobin rise ≥10 g/L (1.0 g/dL) within 2 weeks confirms iron deficiency retrospectively, even if initial iron studies were equivocal 1, 2
• If no response occurs, consider malabsorption, non-adherence, or continued blood loss 5

Prevention of Progression

The CDC recommends periodic screening for anemia among women of childbearing age during routine medical examinations, as most women have inadequate dietary iron intake and heavy menstrual blood loss increases requirements above recommended levels 1

Key preventive measures include:

• Dietary counseling: Emphasize iron-rich foods (red meat, fortified cereals, legumes) and vitamin C to enhance absorption 1, 4
• Address menorrhagia: If heavy menstrual bleeding is identified, gynecologic evaluation for fibroids, endometrial pathology, or hormonal management may be indicated 6
• Continue iron supplementation until ferritin normalizes (typically >50 μg/L), which may require 3-6 months of therapy 7, 4

Important Caveats

Do not pursue extensive GI investigation in an otherwise asymptomatic premenopausal woman with NAID. The British Society of Gastroenterology explicitly states this population has low prevalence of serious GI pathology, and menstrual blood loss is the presumed cause 1

However, if the patient were a man or postmenopausal woman with these same iron studies, bidirectional endoscopy would be mandatory to exclude GI malignancy, as iron deficiency in these populations is never physiologic 1, 7

Ferritin can be falsely elevated by inflammation (it is an acute phase reactant), so if your patient had concurrent infection or inflammatory conditions, a ferritin of 31.9 μg/L might actually represent more severe iron depletion 1, 2