Iron deficiency anemia: symptoms, causes and treatment
In this article
Iron Deficiency: A Global and Invisible Epidemic
Iron deficiencyaffects, worldwide, more than 2 billion people and is one of the nutritional problems most frequently encountered in clinical practice. Although more common in West-Central Africa and South Asia, women of reproductive age and pregnant women together with children during periods of rapid growth constitute the highest-risk groups.
Iron is essential for cellular respiration, energy production, DNA synthesis and cell proliferation. The body recycles iron; for example, iron released through the breakdown of aging red blood cells is recovered. The hormone guarding this balance, hepcidin (hepcidin), finely regulates iron absorption and release. Both deficiency and excess are harmful; maintaining iron balance is therefore critical.
Sections of the Article
- Symptoms of iron deficiency
- Causes of iron deficiency (developing/developed countries, specific risks)
- Diagnostic approach (laboratory testing and differential diagnosis)
- Treatment: Oral and intravenous iron, dosing, side effects
- Special situations: Pregnancy, heart failure, kidney failure, infection risk
- Practical advice and patient education
Iron Biology in Brief: Hepcidin, Absorption and Recycling
- Absorption: Mainly in the duodenum and proximal jejunum. Vitamin C increases absorption; tea/coffee/calcium reduce it.
- Transport & Storage: Transported by transferrin; stored as ferritin and hemosiderin.
- Hepcidin: When elevated, it limits iron release from enterocytes and macrophages; inflammation can increase hepcidin (functional deficiency).
- Recycling: Most iron released by red blood cell breakdown is reused; therefore, chronic blood loss rapidly disrupts the balance.
What Are the Symptoms of Iron Deficiency?
Iron deficiency and iron deficiency anemia often have an insidious course. The proportion of undiagnosed individuals is high.
- Common symptoms: Weakness, easy fatigue, dizziness, palpitations, shortness of breath (on exertion), headache.
- Cognitive/psychosocial: Reduced attention and short-term memory, difficulty concentrating, reduced work/school productivity.
- Physical findings: Pale skin and conjunctiva, spoon-shaped nails (koilonychia), hair loss, cracks at the corners of the mouth.
- Neurological/sleep: May be associated with restless legs syndrome.
- Children/adolescents: Delayed cognitive performance and psychomotor development.
- Pregnancy: Severe deficiency increases premature birth, low birth weight and adverse maternal-infant outcomes.
- Heart failure: Even without anemia, iron deficiency reduces quality of life and exercise capacity.
What Causes Iron Deficiency?
Prominent Causes in Developing Countries
- Inadequate intake and low bioavailability: A diet low in meat and rich in grains; phytates reduce non-heme iron absorption.
- Parasitic infections: Hookworms, schistosomiasis → chronic mixed blood loss.
- Poverty/logistics: Difficulty accessing varied foods, inadequate food fortification programs.
Prominent Causes in Developed Countries
- Dietary pattern: Reliance on non-heme iron in strict vegetarian/near-vegan diets.
- Malabsorption: Celiac disease, atrophic gastritis, H. pylori; long-term PPI use.
- Chronic blood loss: Gastrointestinal tract (ulcers, polyps, angiodysplasia, malignancy), frequent blood donation, menorrhagia.
- Regular blood donors (iron stores may need monitoring).
- NSAIDs and anticoagulant use → occult blood loss.
- End-stage kidney failure: Blood loss during dialysis, inflammation, increased hepcidin.
- Obesity and chronic inflammation: Functional deficiency due to increased hepcidin.
- Heart failure: Iron deficiency prevalence increases; functional capacity is affected.
In this group, iron deficiency anemia may indicate chronic blood loss in the digestive tract and malignancy and other serious causes, including this. Unresponsive to oral treatment or unexplained by the clinical history are cases in which gastroscopy and colonoscopyand, if necessary, video capsule endoscopy are recommended.
Diagnostic Approach: Which Tests and How to Interpret Them?
- Hemoglobin (Hb) & MCV: Anemia often involves microcytosis (low MCV); normocytosis may occur early.
- Ferritin: The most specific indicator of stores; low ferritin supports iron deficiency. Note: Ferritin is an acute-phase reactant; it may be falsely elevated in inflammation.
- Transferrin saturation (TSAT): Low (<%20).
- CRP/ESR: Consider the possibility of “functional iron deficiency” in the presence of inflammation.
- Celiac screening, H. pylori assessment: Especially when oral treatment produces no response.
- sTfR (soluble transferrin receptor): Less affected by inflammation; needed in selected cases.
| Parameter | Expected in Iron Deficiency | Note |
|---|---|---|
| Hb | ↓ (mild-moderate-severe) | May be normal in the early stage |
| MCV | ↓ (microcytosis) | Normocytosis may also occur |
| Ferritin | ↓ | Falsely normal/high with inflammation |
| TSAT | ↓ (<%20) | Transferrin may be ↑ |
| CRP | Normal / ↑ | If ↑, consider functional deficiency |
| sTfR | ↑ | Helpful in selected situations |
Iron Deficiency Treatment
Basic Principle
We manage two aspects together: (1) Iron supplementation to replenish stores, (2) the underlying cause to identify and correct it (blood loss, malabsorption, infection, etc.).
Oral Iron
- Forms: Ferrous sulfate (common), gluconate, fumarate → all are effective.
- Adult dose: Daily 100–200 mg elemental iron (divided doses improve tolerability).
- Children: 3–6 mg/kg/gün elemental iron.
- Increases absorption: Vitamin C (orange juice, tablets), taking on an empty stomach (with a light meal if not tolerated).
- Reduces absorption: Tea, coffee, milk/calcium, antacids/PPIs, phytate-rich foods (separate consumption times).
Treatment duration is generally 3–6 months; the aim is not only to correct Hb, but to bring ferritin back to normal as well.
- Common: Nausea, epigastric discomfort, constipation/diarrhea, metallic taste.
- Tips: Divide the dose, start with a low dose, switch to a different salt, alternate-day dosing can be considered.
- Note: Darkening of stool color is expected and and harmless as an effect.
Intravenous (Parenteral) Iron
- Indications (summary): Severe deficiency and a need for rapid correction, no response to oral treatment, marked malabsorption, IBD flare, chronic kidney failure (specific protocols), etc.
- Advantages: Rapid replenishment of stores, no dependence on intestinal absorption.
- Disadvantages: Cost, rare hypersensitivity risk; in a hospital setting, with slow infusion and close observation.
Approximate dose calculation: Weight(kg) × 2.3 × Hb requirement (g/dL) + 500–1000 mg (for stores). The administration regimen varies according to the preparation used.
With clear signs of tissue hypoxia (angina, severe heart failure) and severe symptomatic anemia present, packed red blood cells may be needed. Each 1 unit contains ~200 mg iron ; however, the underlying cause must still be investigated.
In areas where malaria is endemic, large-scale iron supplementation programs can affect parasitemia; the risk-benefit balance must be considered carefully, accompanying malaria control strategies should be integrated with them.
Special Situations
- Pregnancy: Increased requirements → screening and prophylaxis policies; if not tolerated, IV options according to trimester and guidelines.
- Heart Failure: Iron deficiency (with/without anemia) reduces functional capacity; IV iron may be considered in certain subgroups.
- Chronic Kidney Failure: IV iron is frequently used in dialysis; combined strategies with ESA.
- Obesity/Inflammation: Functional deficiency due to elevated hepcidin; managing the underlying inflammation is essential.
Practical Advice and Patient Education
- Take your iron medicine Vitamin C with it and separately from tea/coffee when taking the medicine.
- PPI/antacid use should be separated in time; if necessary, plan dose reduction/an alternative with your physician.
- An Hb response is expected in 3–4 weeks; to replenish stores continue treatment for 3–6 months.
- If side effects occur, divide the dose, change formulation or alternate-day ask about this strategy.
- If there is no response: adherence, H. pylori/celiac disease, blood loss should be investigated.
Quick FAQ
Can my ferritin be normal while my iron is low? Ferritin rises in inflammation; interpret it together with TSAT and the clinical context.
What should people on plant-based diets consider? Intake with vitamin C, preparation methods that reduce phytates (soaking, fermentation), supplementation if necessary.
When is endoscopy needed? A low threshold in men, postmenopausal women, lack of response or unexplained anemia.
Conclusion: Managing Iron Deficiency Is a Marathon
Iron deficiency is common and often unnoticed, but its effects are extensive as a problem. Successful management relies on accurate diagnosis, appropriate supplementation and the underlying cause being carefully corrected. With individualized dosing, side-effect management and IV iron options when necessary, long-term recurrences can be prevented.
Note: This content is intended to inform physicians; individual clinical circumstances and current guidelines should guide patient management.
Sources
Iron-Deficiency Anemia.
N Engl J Med 2015
Was this article helpful?
Your feedback helps us improve our content.
Reader comments
Share your comment
Your name and comment are published only after administrator approval. Your email address is never shown to visitors.
Be the first to comment.