Iron is an essential nutrient that is required for red blood cell formation. It is a key component of hemoglobin, which carries oxygen throughout the body. Measurement of blood iron is often combined with other analyses as part of iron studies.

Transferrin is a protein that transports iron in the body. It also regulates the absorption of iron. Transferrin is correlated with total iron-binding capacity (TIBC), which quantifies the blood's ability to transport iron.

Ferritin, meanwhile, acts as the main iron reserve in the cells, particularly in the liver, bone marrow, spleen, and muscles. It can also be found in smaller quantities in the blood. Blood ferritin levels are a reflection of the body's iron stores.

Below is a summary of the analyses included in iron studies:

• The serum iron, which directly measures the amount of iron in the blood
• The transferrin, which measures the amount of a protein that transports iron throughout the body
• The total iron-binding capacity (TIBC), which informs about the ability of iron to bind to transferrin and other proteins in the blood
• The serum ferritin, which gives an idea of iron stores

Serum iron

• Hemochromatosis
• Hemolytic anemia
• Lead or iron poisoning
• Liver damage

Ferritin

• Hemochromatosis
• Frequent blood transfusions
• Underlying illnesses (such as cancer or an inflammatory disease)
• Too much iron in your diet
• Thyroid disorders (hyperthyroidism)
• Disorders related to alcohol consumption

Transferrin and TIBC

• Iron deficiency (iron deficiency anemia, acute bleeding)

Serum iron

• Iron deficiency anemia
• Thalassemia
• Dietary deficiency
• Intestinal malabsorption
• Loss due to gastrointestinal bleeding

Ferritin

• Iron deficiency (due to bleeding, dietary deficiency, increased requirements, etc.)

Transferrin and TIBC

• Certain inflammatory diseases
• Liver damage