What is the appropriate workup for iron deficiency anemia (IDA)?

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Last updated: May 22, 2025 • View editorial policy

From the Guidelines

The workup for iron deficiency should begin with a complete blood count (CBC) and iron studies, including serum iron, total iron binding capacity (TIBC), ferritin, and transferrin saturation, as recommended by the British Society of Gastroenterology guidelines for the management of iron deficiency anaemia in adults 1, 2, 3.

Initial Evaluation

The initial evaluation of iron deficiency should include a thorough medical history and physical examination to identify potential causes of iron deficiency, such as heavy menstrual bleeding, gastrointestinal blood loss, or malabsorption.

  • A ferritin level below 30 ng/mL is diagnostic of iron deficiency, while levels between 30-100 ng/mL may indicate iron deficiency in the presence of inflammation.
  • Serum iron, TIBC, and transferrin saturation should also be measured to assess iron stores and identify potential causes of iron deficiency.

Treatment

Treatment of iron deficiency involves oral iron supplementation, typically ferrous sulfate 325 mg daily or twice daily, taken on an empty stomach with vitamin C to enhance absorption 3.

  • Ferrous sulfate is the recommended initial treatment for iron deficiency anaemia, with a dose of 50-100 mg of elemental iron per day 1.
  • For patients who cannot tolerate oral iron, intravenous iron formulations like iron sucrose or ferric carboxymaltose can be used.
  • Parenteral iron should be considered when oral iron is contraindicated, ineffective, or not tolerated 3.

Monitoring and Follow-up

Follow-up hemoglobin checks should be performed after 2-4 weeks of treatment, with iron studies repeated after 3 months to confirm repletion of iron stores 3.

  • Regular monitoring of hemoglobin levels is essential to ensure an adequate response to treatment and to detect potential recurrence of iron deficiency.
  • The underlying cause of iron deficiency must be addressed to prevent recurrence, and additional testing may include celiac disease screening, Helicobacter pylori testing, and urine analysis if appropriate.

From the FDA Drug Label

Inclusion criteria prior to randomization included hemoglobin (Hb) <12 g/dL, ferritin ≤100 ng/mL or ferritin ≤300 ng/mL when transferrin saturation (TSAT) ≤30%. Iron deficiency was defined as serum ferritin <100 ng/mL or 100 to 300 ng/mL with TSAT <20%.

The workup for iron deficiency includes checking hemoglobin (Hb) levels, ferritin levels, and transferrin saturation (TSAT).

  • Hemoglobin (Hb): <12 g/dL
  • Ferritin: ≤100 ng/mL or ≤300 ng/mL when TSAT ≤30%
  • Transferrin saturation (TSAT): ≤30% or ≤20% in certain cases 4

From the Research

Iron Deficiency Workup

  • Iron deficiency anemia and pre-anemic iron deficiency are the most frequent pathologies, with oral iron supplementation being the first line of treatment 5
  • The simplest and most commonly prescribed oral iron supplement is ferrous sulfate, although other ferrous salts and ferric complexes are also widely used 5
  • Novel iron formulations, such as ferric maltol and nanoparticle encapsulated sucrosomial iron, have been developed to improve efficacy and reduce gastrointestinal side effects 5

Treatment Selection

  • Iron deficiency treatment selection is driven by several factors, including the presence of inflammation, the time available for iron replenishment, and the anticipated risk of side-effects or intolerance 6
  • Intravenous iron preparations are indicated for the treatment of iron deficiency when oral preparations are ineffective or cannot be used, and have applicability in a wide range of clinical contexts 6
  • Oral iron supplementation is often the first-line treatment for the acute and chronic management of iron deficiency, but there is no consensus on the optimal formulation or dosing strategy 7

Comparison of Oral Iron Supplements

  • Iron protein succinylate (Ferplex) has been shown to be equally effective as ferrous sulphate in the treatment of iron deficiency anemia, with a better tolerability profile 8
  • A comparative study found that both ferrous sulphate and iron protein succinylate were effective in restoring hemoglobin, hematocrit, and erythrocytes, with no statistical differences between treated groups and control 8
  • Intravenous iron sucrose has been compared to oral iron sulfate in the treatment of iron deficiency anemia in patients with inflammatory bowel disease, with results suggesting a better gastrointestinal tolerability for iron sucrose 9

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.