In a 22-year-old female with hemoglobin 12.2 g/dL, hematocrit 35.9 %, serum iron 88 µg/dL, and ferritin 30.8 ng/mL, is this iron‑deficiency anemia?

Is This Iron Deficiency Anemia?

No, this is not iron deficiency anemia—this is iron deficiency without anemia. The hemoglobin of 12.2 g/dL is within the normal range for women (WHO defines anemia in women as Hb <12 g/dL), but the ferritin of 30.8 ng/mL indicates depleted iron stores 1, 2, 3.

Understanding the Laboratory Values

Your patient has:

• Hemoglobin 12.2 g/dL: Normal (just above the 12 g/dL threshold for anemia in women)
• Hematocrit 35.9%: Low-normal range
• Serum iron 88 µg/dL: Within normal limits
• Ferritin 30.8 ng/mL: This confirms iron deficiency

Why This Matters

A ferritin <45 ng/mL is diagnostic of iron deficiency in patients without inflammation, with 85% sensitivity and 92% specificity 2. Your patient's ferritin of 30.8 ng/mL falls well below this threshold. More specifically, ferritin <30 ng/mL indicates low body iron stores even in the absence of anemia 4, 1.

The British Society of Gastroenterology guidelines are explicit: ferritin <30 μg/L is "generally indicative of low body iron stores" 1. The most recent AGA guidelines (2020) recommend using a ferritin cut-off of 45 ng/mL for optimal sensitivity-specificity balance, but acknowledge that levels <30 ng/mL are clearly abnormal 2, 5.

Clinical Significance

Iron deficiency without anemia is clinically important and warrants treatment. Recent evidence shows that women with iron deficiency without anemia experience similar symptoms to those with iron deficiency anemia—including fatigue, exercise intolerance, and cognitive difficulties 6. These symptoms improve with iron supplementation even when hemoglobin is normal 3, 6.

What You Need to Do Next

1. Investigate the underlying cause: Even without anemia, ferritin this low in a 22-year-old woman requires evaluation:

   • Most likely: Heavy menstrual bleeding (accounts for most cases in premenopausal women) 1, 7
   • Dietary assessment: Vegetarian/vegan diet, inadequate iron intake 3
   • Celiac disease screening: Check tissue transglutaminase antibodies (tTG) 7, 2
   • H. pylori testing: Non-invasive testing recommended 2, 5
   • GI investigation is NOT needed in a premenopausal woman with an obvious cause like menorrhagia 1, 7

2. Initiate iron replacement therapy:

   • Start oral iron: Ferrous sulfate 65 mg elemental iron every other day (improves absorption and reduces side effects) 3
   • Alternative: 3-6 mg/kg/day of elemental iron if more rapid repletion needed 3, 8
   • Target ferritin >50 ng/mL to replete stores 1, 5

3. Follow-up in 2-4 weeks: Check hemoglobin and ferritin to assess response 3

Important Caveats

• If inflammatory markers were elevated (CRP, ESR), you would need a higher ferritin threshold (100 ng/mL) to exclude iron deficiency 4. However, there's no indication of inflammation in this case.

• Transferrin saturation would add diagnostic value if available—a TSAT <16% would further confirm iron deficiency 4, 9. However, with ferritin this low, the diagnosis is already clear.

• Don't wait for anemia to develop before treating. The goal is to prevent progression to IDA and address symptoms of iron deficiency 5, 3, 6.