I am a 21‑year‑old with blood group O positive, normal serum iron, low ferritin (17 µg/L), high‑normal transferrin, and low‑normal transferrin saturation, and I am planning to get married next month; how should I manage this early iron deficiency?

Management of Early Iron Deficiency in a Young Woman Planning Marriage

You should begin oral iron supplementation immediately with ferrous sulfate 65 mg elemental iron daily (or alternate-day dosing) and continue for at least 3 months to restore your depleted iron stores before conception, given your ferritin of 17 µg/L confirms early iron deficiency despite normal hemoglobin. 1

Understanding Your Laboratory Results

Your iron studies reveal early-stage absolute iron deficiency characterized by:

• Ferritin 17 µg/L is below the threshold of 20 µg/L, indicating depleted body iron stores even though it sits just above the 15 µg/L cutoff that has 99% specificity for absolute deficiency 1
• Transferrin saturation of 0.15 (15%) falls at the lower limit of normal, confirming that iron delivery to your bone marrow for red blood cell production is already borderline impaired 1
• High-normal transferrin (3.4 g/L) reflects your body's compensatory attempt to capture more circulating iron when stores are low 1
• Normal serum iron and hemoglobin indicate you are in Stage 1 iron deficiency—stores are depleted but anemia has not yet developed 2

Why Immediate Treatment Matters Before Pregnancy

• Pregnancy dramatically increases iron requirements, and women entering pregnancy with depleted stores (ferritin <30 µg/L) have a 65% risk of developing iron deficiency and functional impairment by term, even without frank anemia 3
• Iron stores require 3–6 months to replenish after starting supplementation, making pre-conception treatment critical 2
• Iron deficiency without anemia still causes significant symptoms including fatigue, reduced exercise tolerance, and impaired cognitive function that can affect quality of life 2

Recommended Treatment Protocol

Oral Iron Supplementation

• Start ferrous sulfate 65 mg elemental iron daily (one 325 mg tablet contains ~65 mg elemental iron) 2
• Alternate-day dosing (60–65 mg every other day) improves absorption by 30–50% and reduces gastrointestinal side effects like nausea and constipation if daily dosing is poorly tolerated 2
• Take on an empty stomach for optimal absorption, or with meals if gastrointestinal symptoms occur 2
• Continue for at least 3 months to achieve target ferritin >100 µg/L, which fully restores iron reserves and prevents rapid recurrence 2

Expected Response

• Hemoglobin should rise ≥10 g/L within 2 weeks if iron deficiency is the sole cause (though yours is already normal) 2
• Ferritin will lag behind hemoglobin normalization because absorbed iron is preferentially used for red blood cell production before refilling storage compartments 2

Screening for Underlying Causes

Although heavy menstrual bleeding is the most common cause of iron deficiency in premenopausal women, you should undergo targeted screening:

• Screen for celiac disease with tissue transglutaminase IgA antibodies, as celiac disease accounts for 3–5% of iron deficiency cases and can cause treatment failure if missed 2
• Test for Helicobacter pylori infection (stool antigen or urea breath test), which impairs iron absorption 2
• Assess your menstrual blood loss history to determine if heavy menses are contributing 2

When to Consider Endoscopy

You do NOT need immediate gastrointestinal endoscopy because you are a young premenopausal woman without alarm symptoms. Reserve bidirectional endoscopy only if: 2

• You develop gastrointestinal symptoms (abdominal pain, altered bowel habits, visible blood in stool)
• Celiac or H. pylori testing is positive and requires confirmation
• You fail to respond to adequate oral iron after 8–10 weeks
• You have a strong family history of colorectal cancer

Follow-Up Monitoring

• Recheck complete blood count and ferritin at 8–10 weeks to assess response to treatment 2
• Target ferritin >100 ng/mL before conception to ensure adequate reserves for pregnancy 2
• If ferritin fails to rise despite adequate supplementation, this signals ongoing blood loss or malabsorption and warrants urgent evaluation 2

When to Switch to Intravenous Iron

Consider intravenous ferric carboxymaltose (15 mg/kg, maximum 1000 mg per dose) if: 2

• You develop severe oral iron intolerance (marked nausea, constipation, diarrhea)
• Celiac disease or other malabsorption is confirmed
• You fail to respond to 8–10 weeks of adequate oral therapy
• You become pregnant before stores are replenished (second/third trimester indication)

Critical Pitfalls to Avoid

• Do not assume your "borderline" ferritin of 17 µg/L is acceptable—values <30 µg/L indicate depleted stores that require treatment, and pregnancy will rapidly exhaust these minimal reserves 1, 2
• Do not stop iron supplementation once you feel better or hemoglobin normalizes—you must continue for 3 months after hemoglobin normalization to achieve ferritin >100 µg/L 2
• Do not skip celiac disease screening—its 3–5% prevalence in iron deficiency means missing this diagnosis leads to treatment failure and persistent symptoms 2
• Do not delay treatment while awaiting test results—begin oral iron immediately, as early intervention prevents progression to anemia and optimizes pre-conception iron status 2