What does a ferritin level of 7, transferrin saturation of 16%, iron binding capacity of 435, and iron total of 68 indicate about a patient's iron status?

Iron Deficiency Without Anemia

These laboratory values indicate iron deficiency without anemia—your ferritin of 7 ng/mL is severely depleted (well below the 15-30 ng/mL threshold), your transferrin saturation of 16% confirms inadequate iron availability for red blood cell production, and your elevated iron binding capacity of 435 reflects your body's compensatory attempt to capture more circulating iron. 1

Interpretation of Your Specific Values

Your iron panel reveals a classic pattern of absolute iron deficiency:

• Ferritin 7 ng/mL: This is profoundly low and indicates virtually absent iron stores. A ferritin <15 ng/mL has 99% specificity for iron deficiency in the absence of inflammation. 1 Even more conservative thresholds suggest ferritin <30 ng/mL indicates depleted body iron stores. 1, 2

• Transferrin saturation 16%: This sits at the diagnostic threshold. Transferrin saturation <16% confirms iron deficiency and indicates iron-restricted erythropoiesis (your bone marrow cannot access sufficient iron to make red blood cells normally). 1

• Total iron binding capacity (TIBC) 435: This is elevated, which occurs when your body increases transferrin production to try to capture more of the limited circulating iron. TIBC rises when iron stores are depleted. 1

• Serum iron 68: This is low, reflecting inadequate circulating iron available for cellular processes. 1

Clinical Significance

You have iron deficiency that has progressed beyond simple depletion of stores—you are now experiencing iron-restricted erythropoiesis, meaning your body cannot produce red blood cells optimally. 2 This stage precedes frank iron deficiency anemia but can still cause significant symptoms. 2, 3

Symptoms to Assess

Even without anemia, iron deficiency at this severity commonly causes: 2

• Fatigue and exercise intolerance
• Difficulty concentrating and irritability
• Restless legs syndrome (affects 32-40% of iron deficient patients)
• Pica (craving ice, dirt, or other non-food items—occurs in 40-50%)
• Depression
• Dyspnea with exertion

Underlying Causes Requiring Investigation

The critical next step is identifying why you are iron deficient. 2, 3 The most common causes include:

• Recurrent blood loss (responsible for 94% of cases): 3

  • Heavy menstrual bleeding (if premenopausal woman)
  • Gastrointestinal bleeding (ulcers, gastritis, polyps, malignancy)
  • Frequent blood donation

• Impaired absorption: 2

  • Celiac disease (requires testing)
  • Atrophic gastritis or H. pylori infection
  • Post-bariatric surgery
  • Inflammatory bowel disease

• Inadequate dietary intake: 2

  • Vegetarian/vegan diet without supplementation
  • Low socioeconomic status limiting food access

• Medications: 2

  • Chronic NSAID use causing occult GI bleeding
  • Proton pump inhibitors reducing iron absorption

Recommended Evaluation

If you are a man or postmenopausal woman, bidirectional endoscopy (colonoscopy and upper endoscopy) should be performed to exclude gastrointestinal malignancy or other bleeding sources. 3 Nine percent of patients over 65 with iron deficiency have gastrointestinal cancer. 4

If you are a premenopausal woman with heavy menstrual bleeding, treatment of the bleeding plus iron supplementation is reasonable without immediate endoscopy. 3, 4 However, if you fail to respond to treatment, further investigation is warranted.

All patients should be tested for: 3

• H. pylori infection (common cause of iron deficiency)
• Celiac disease (tissue transglutaminase antibody)
• Inflammatory markers (CRP) to assess for chronic inflammation

Treatment Approach

Oral iron supplementation is first-line therapy: ferrous sulfate 325 mg daily or every other day (every-other-day dosing improves absorption and reduces side effects). 2, 3

Intravenous iron is indicated if you have: 2, 3

• Intolerance to oral iron (affects ~50% of patients)
• Malabsorption conditions (celiac disease, post-bariatric surgery)
• Chronic inflammatory conditions (inflammatory bowel disease, chronic kidney disease, heart failure)
• Ongoing blood loss
• Pregnancy (second or third trimester)

Response should be assessed in 2-4 weeks with repeat hemoglobin and iron studies. 3 Failure to respond suggests either continued blood loss, malabsorption, or non-adherence, and should prompt consideration of intravenous iron or further investigation. 3, 4

Important Caveats

Ferritin is an acute phase reactant—if you have any inflammatory condition (infection, autoimmune disease, malignancy), your ferritin may be falsely elevated. 1 In the presence of inflammation, ferritin <100 ng/mL can still indicate iron deficiency. 1 Check CRP to assess for inflammation. 1

Your transferrin saturation of exactly 16% sits at the diagnostic threshold, which has only 20% sensitivity but 93% specificity for iron deficiency. 1 Combined with your severely low ferritin, the diagnosis is certain. 1