What is ferritin?

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From the Guidelines

Ferritin is a protein that stores iron in the body and releases it when needed, with normal levels ranging from 20-250 ng/mL for adult females and 30-300 ng/mL for adult males, as indicated by recent studies 1.

Definition and Function of Ferritin

Ferritin serves as the primary storage form of iron, protecting cells from the potentially toxic effects of free iron while maintaining a readily available supply for essential bodily functions. It's found in most body tissues, with particularly high amounts in the liver, spleen, bone marrow, and muscles. Blood ferritin levels are commonly measured through a simple blood test to assess iron status in the body.

Importance of Ferritin Levels

Low ferritin levels indicate iron deficiency, which can lead to anemia if left untreated, while high levels may suggest iron overload conditions, inflammation, liver disease, or certain types of cancer. Maintaining proper ferritin levels is crucial for oxygen transport, energy production, immune function, and many enzymatic reactions throughout the body. According to a recent study, serum ferritin should be maintained within the range of 50-100 lg/L to avoid iron deficiency and iron overload 1.

Clinical Significance of Ferritin

In patients with hemochromatosis, serum ferritin levels are used to monitor the effectiveness of phlebotomy treatment, with a target level of 50-100 lg/L 1. In patients with inflammatory bowel disease, serum ferritin levels can be used to diagnose iron deficiency anemia, with a level < 30 mg/L indicating iron deficiency in the absence of inflammation 1. In patients with cancer, functional iron deficiency can occur due to inflammation, and serum ferritin levels can be used to diagnose and monitor this condition 1.

Key Points to Consider

  • Normal ferritin levels: 20-250 ng/mL for adult females and 30-300 ng/mL for adult males
  • Low ferritin levels: indicate iron deficiency, which can lead to anemia
  • High ferritin levels: may suggest iron overload conditions, inflammation, liver disease, or certain types of cancer
  • Target ferritin level for patients with hemochromatosis: 50-100 lg/L
  • Diagnosis of iron deficiency anemia in patients with inflammatory bowel disease: serum ferritin level < 30 mg/L in the absence of inflammation.

From the Research

Definition and Function of Ferritin

  • Ferritin is an intracellular iron storage protein that stores surplus iron after all cellular needs are fulfilled and releases it in the face of an acute demand 2.
  • It is composed of 24 subunits that form an almost spherical shell delimiting a cavity where thousands of iron atoms can be stored in a nontoxic ferric form 3, 4.
  • Ferritin can accumulate up to 4500 iron atoms as a ferrihydrite mineral in a protein shell and releases these iron atoms when there is an increase in the cell's need for bioavailable iron 3.

Role of Ferritin in Iron Regulation

  • Ferritin plays a critical role in iron metabolism and regulation, and its concentration in the plasma or serum reflects iron stores 5, 6.
  • Low ferritin indicates iron deficiency, while elevated ferritin reflects risk of iron overload 5.
  • Serum ferritin serves as a reliable indicator of both iron stores and inflammatory conditions 4.

Structure and Synthesis of Ferritin

  • The ferritin protein shell consists of 24 protein subunits of two types, the H-subunit and the L-subunit, which perform different functions in the mineralization process of iron 3.
  • The synthesis of ferritin is regulated both transcriptionally and translationally, and is controlled by an iron-responsive element present in the 5'-untranslated region of the ferritin subunit mRNA 3.
  • The levels of intracellular ferritin are determined by the balance between synthesis and degradation 3.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

A Brief History of Ferritin, an Ancient and Versatile Protein.

International journal of molecular sciences, 2024

Research

Serum or plasma ferritin concentration as an index of iron deficiency and overload.

The Cochrane database of systematic reviews, 2021

Research

The measurement and interpretation of serum ferritin.

Annals of clinical and laboratory science, 1980

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.

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