From the Guidelines
Low iron levels with normal ferritin typically indicate early-stage iron deficiency or functional iron deficiency, and treatment with oral iron supplements such as ferrous sulfate may be necessary. According to the British Society of Gastroenterology guidelines for the management of iron deficiency anaemia in adults 1, serum ferritin is the most specific test for iron deficiency in the absence of inflammation. However, in cases where ferritin levels are normal, other markers such as low transferrin saturation, low iron, and raised total iron-binding capacity can indicate iron deficiency.
Some key points to consider in the diagnosis and treatment of low iron with normal ferritin include:
- The specificity of mean cell volume (MCV) and mean cell Hb (MCH) for iron deficiency is limited, as microcytosis and hypochromia also occur in many haemoglobinopathies and anaemia of chronic disease 1
- Serum ferritin (SF) is an acute phase protein, and apparently normal levels may occur with iron deficiency in the context of an inflammatory disease process, with an SF cut-off of 45 μg/L suggested as providing the optimal trade-off between sensitivity and specificity for iron deficiency in practice 1
- Treatment with oral iron supplements such as ferrous sulfate (325 mg, containing 65 mg elemental iron) taken 1-3 times daily between meals with vitamin C to enhance absorption may be recommended, with common supplements including ferrous sulfate, ferrous gluconate, or ferrous fumarate 1
- Additional tests like transferrin saturation, total iron binding capacity (TIBC), or complete blood count may be ordered to better understand the patient's iron status and determine the underlying cause before starting treatment.
It is essential to consult with a healthcare provider for proper diagnosis and treatment, as the underlying cause of low iron with normal ferritin can be complex and require individualized management.
From the Research
Iron Deficiency with Normal Ferritin Levels
- Iron deficiency is defined as low iron stores with or without anemia, and it can progress to iron-deficiency anemia if left untreated 2.
- Ferritin is an iron storage protein, and its concentration in the plasma or serum reflects iron stores; low ferritin indicates iron deficiency, while elevated ferritin reflects risk of iron overload 3.
- However, it is possible to have low iron levels with normal ferritin levels, as ferritin is also an acute-phase protein and its levels can be elevated in inflammation and infection 3.
- The most common causes of iron deficiency are bleeding (menstrual, gastrointestinal), impaired iron absorption (atrophic gastritis, celiac disease, bariatric surgical procedures), inadequate dietary iron intake, and pregnancy 2.
Diagnosis and Treatment of Iron Deficiency
- Testing for iron deficiency is indicated for patients with anemia and/or symptoms of iron deficiency (fatigue, pica, or restless legs syndrome) and should be considered for those with risk factors such as heavy menstrual bleeding, pregnancy, or IBD 2.
- Iron deficiency is diagnosed by low serum ferritin (typically <30 ng/mL) in individuals without inflammatory conditions or by transferrin saturation (iron/total iron binding capacity × 100) less than 20% 2.
- Oral iron (ferrous sulfate 325 mg/d or on alternate days) is typically first-line therapy for iron deficiency, while intravenous iron is indicated for patients with oral iron intolerance, poor absorption, or certain chronic inflammatory conditions 2.
- Lactoferrin supplementation has been shown to have better effects on serum iron, ferritin, and hemoglobin concentration compared to ferrous sulfate, and may be a suitable alternative for patients with gastrointestinal side effects 4.
Management of Iron Deficiency with Normal Ferritin Levels
- In cases where iron deficiency is suspected despite normal ferritin levels, further testing such as transferrin saturation or reticulocyte hemoglobin may be necessary to confirm the diagnosis 3.
- Treatment of iron deficiency with normal ferritin levels should be individualized and based on the underlying cause of the deficiency, as well as the presence of any inflammatory or chronic conditions 2.
- Vitamin C supplementation may also be beneficial in preventing liver damage induced by iron overload, and may be considered as an adjunct to iron therapy 5.