From the Guidelines
Serum ferritin levels are a crucial indicator of iron stores in the body, with low levels suggesting iron deficiency and high levels indicating iron overload or inflammation. Ferritin levels reflect the amount of iron stored in the liver, spleen, and bone marrow reticuloendothelial cells 1. A normal ferritin level indicates adequate iron reserves, while low levels suggest iron deficiency, which may lead to anemia if left untreated. According to the most recent guidelines, in the presence of inflammation, a serum ferritin up to 100 mg/L may still be consistent with iron deficiency 1.
Key Points to Consider
- Normal ferritin ranges are typically 20-250 ng/mL for women and 30-300 ng/mL for men, though reference ranges vary by laboratory.
- Low ferritin levels can indicate iron deficiency, which may lead to anemia if left untreated.
- High ferritin levels can indicate iron overload conditions like hemochromatosis, or inflammation from infections, liver disease, or certain cancers.
- Ferritin is particularly valuable as a diagnostic tool because it decreases before hemoglobin levels fall in iron deficiency, allowing earlier intervention before anemia develops.
Diagnosis and Treatment
- In patients without clinical, endoscopic, or biochemical evidence of active disease, serum ferritin <30 mg/L is an appropriate criterion for the diagnosis of iron deficiency anemia 1.
- Iron supplementation is recommended in all patients with iron-deficiency anemia, and intravenous iron should be considered as first-line treatment in patients with clinically active disease or previous intolerance to oral iron 1.
- Treatment of iron deficiency anemia should be guided by serum ferritin levels, with the goal of replenishing iron stores and improving quality of life. After successful treatment, re-treatment with intravenous iron should be initiated as soon as serum ferritin drops below 100 mg/L or hemoglobin below 120 or 130 g/L according to gender 1.
From the Research
Serum Ferritin Levels and Iron Stores
- Serum ferritin levels are often used as an indicator of iron stores in the body 2, 3, 4, 5, 6
- Studies have shown that serum ferritin iron can be a simple and direct measure of iron stores, unconfounded by inflammation 2
- However, the correlation between serum ferritin levels and body iron stores can be affected by various factors, such as inflammation and liver damage 3, 5
Diagnostic Value of Serum Ferritin
- Serum ferritin has been used as a diagnostic tool for iron deficiency anemia, but its accuracy can be limited in certain populations, such as the elderly 5
- A study found that a serum ferritin cutoff level of 100ng/mL could differentiate patients with and without iron deficiency anemia with a sensitivity of 60% and specificity of 59% in an elderly cohort 5
- Another study found that serum ferritin was the best predictor of body iron stores in patients with hemochromatosis, but the correlation was not very strong 6
Relationship Between Serum Ferritin and Iron Stores
- Research has shown that the iron content of serum ferritin can be correlated to individual liver iron concentrations, but the correlation can be poor in patients with certain conditions, such as hemochromatosis and beta-thalassemia major 3
- A study found that the ferritin-per-hemosiderin ratio was almost the same in patients with hereditary hemochromatosis and chronic hepatitis C, indicating a similar localized hepatic hemosiderin deposition in both conditions 4
- The iron storing capacity of hemosiderin was found to be limitless, while that of ferritin was suppressed when ferritin iron exceeded around 5 grams 4