Iron

Iron is an important mineral that your body needs to stay healthy. Your body uses iron to make hemoglobin, the protein in your red blood cells that carries oxygen throughout your body. If you don’t have enough iron, you may not have enough hemoglobin. This condition is called iron deficiency anemia.

Iron in your body is carried, or bound, mainly to a protein made by your liver called transferrin. The TIBC test is based on certain proteins, including transferrin, found in the blood. Your transferrin levels are almost always measured along with iron and TIBC.

Iron plays a principal role in erythropoiesis, the formation and maturation of red blood cells (RBCs) and is required for hemoglobin synthesis. The human body contains between four and five grams of iron, about 65% of which is present in hemoglobin and 3% of which is present in myoglobin, the oxygen storage protein found in skeletal muscle and cardiac muscle. A small amount is also found in cellular enzymes that catalyze the oxidation and reduction of iron. Excess iron is stored in the liver and spleen as ferritin and hemosiderin. Any iron present in the serum is in transit between the digestive track and bone marrow, and available iron stores forms. Sixty to 70% of the body’s iron is carried by its specific transport protein, transferrin. For this reason, total iron binding capacity (TIBC) and transferrin are sometimes referred to interchangeable, even though other proteins carry iron and contribute to the TIBC.

Unbound iron is highly toxic, but there is generally an excess of transferrin available to prevent the buildup of unbound iron in the circulation. The percentage of iron saturation is calculated by dividing the serum iron value by the TIBC value and multiplying it by 100.

TIBC

• Assist in the diagnosis of iron deficiency anemia.
• Differentiate between iron deficiency anemia and anemia secondary to chronic disease.
• Monitor hematological response to therapy during pregnancy and iron deficiency anemias.
• Provide support for diagnosis of hemochromatosis or diseases of iron metabolism and storage.

Ferritin

Ferritin is a protein found in the bloodstream which stores iron. Ferritin helps in transporting iron where it’s most needed in the body. Too much or too little ferritin can cause a lot of health issues and that’s why you should check it often.