IRON TOTAL and Iron Binding Capacity IBC

Also Known As: Iron Binding Capacity Test, TIBC Test, TIBC, Serum Iron Binding Capacity, UIBC

What Is An Iron Total, And Total Iron Binding Capacity Test?

Along with other iron tests, the iron, total, and total iron-binding capacity test is performed to assess your body's ability to transport iron in the bloodstream. It also helps diagnose iron deficiency or iron overload in the body. Iron is present in all of your body cells. Therefore, this test is a type of blood test that calculates whether there is too much or too little of this mineral in your blood. You get the iron your body requires through diet. It is abundantly found in various food items, including:

• Beans
• Dark green, leafy vegetables like spinach
• Poultry
• Seafood
• Eggs
• Whole grains

Once iron enters your body, it travels through your blood through a protein called transferrin, produced by the liver. This test is the evaluation of the way transferrin carries iron in the blood. After binding to transferrin, the iron goes to your bone marrow directly to produce red blood cells and hemoglobin, i.e., a protein that helps carry oxygen. You will find two types of iron-binding capacity, unsaturated iron-binding capacity, and total iron-binding capacity. UIBC measures how much transferrin is not yet bound to the iron, whereas the TIBC test measures the total amount of iron in your blood plus the unsaturated iron-binding capacity.

What Is The Test Used For?

Transferrin is the integral protein of your blood that binds to the iron and transfers it throughout your body cells and tissues. This test directly measures the level of transferrin in the blood. Alternatively, your doctor can indirectly measure the transferrin level to express it as the amount of iron it is capable of binding. This procedure is called the total iron-binding capacity test. As stated above, iron is a crucial nutrient that, along with other functions, is required to make healthy red blood cells. It plays a critical role in producing hemoglobin and circulating oxygen to all parts of your body. Normally the iron is transported throughout your body using transferrin produced by the liver.

A major portion of iron is incorporated in hemoglobin within the red blood cells in healthy individuals. The remainder is stored in the tissues in the form of ferritin, hemosiderin, and other small amounts needed to produce proteins like myoglobin and enzymes. The total iron and total iron-binding capacity test, along with UIBC and transferrin saturation test, help evaluate the amount of iron in your body via measurement of other substances in the blood. Several other tests are also often ordered with this test simultaneously, and then the results are interpreted together to diagnose a medical condition and monitor iron deficiency or iron overload in the body.

Why And When Do You Need An Iron, Total, And Total Iron Binding Capacity Test?

Your doctor or health care provider can perform this test to check for medical conditions leading to abnormal iron levels in your body. It is often recommended if you are experiencing symptoms related to iron deficiency anemia. Anemia is a condition characterized by a low red blood cell or hemoglobin count. Iron deficiency is considered a critical nutritional deficiency that is usually the main cause of anemia. However, iron deficiency can also be triggered by other conditions like pregnancy in rare cases.

The symptoms of low iron levels or iron-deficiency anemia include:

• Paleness
• Constant feeling of tiredness and fatigue
• Weakness
• Increased frequency of infections
• Swollen tongue
• Always feeling cold
• Delayed mental development (especially in children)
• Difficulty concentrating at work

Your doctor will order this test if they suspect you have excessive iron in your blood. High levels of iron most commonly demonstrate an underlying medical condition. Still, in some cases, it can be due to an overdose of iron supplements and vitamins. The signs and symptoms of iron overload or hereditary hemochromatosis include:

• Painful joints
• Constant feeling of tiredness and weakness
• Abdominal pain
• Changes in the skin color to bronze or grey
• Low sex drive
• Unexpected weight loss
• Irregular heart rhythm
• Hair loss
• Organ damage, including heart and liver

What Kind Of Sample Is Required For The Test?

This test involves taking a small sample of your blood. During the procedure, blood is usually drawn from a vein of your hand or the bend of the elbow. The health care provider or lab technician will first find a suitable vein to insert the needle to take the sample. Expect a slight stinging or pricking sensation when the needle goes in; however, the overall test is not painful at all. Your doctor will only collect enough blood needed to perform the test and other related procedures recommended by a doctor.

Do You Need To Prepare For The Test?

For this test, fasting for at least 8 to 10 hours is necessary to ensure the most accurate results. 
It means that you cannot eat or drink anything before taking the total iron and total iron-binding capacity test. Certain medications can also alter the test results, so you must tell your doctor about your prescriptions and use of over-the-counter medications. The medications affecting the test results include birth control pills, adrenocorticotropic hormone, chlorides, and chloramphenicol antibiotics.

Are There Any Risks To This Test?

The blood test poses a few risks and complications. Some individuals may experience slight bruising or soreness around the area where the syringe was inserted. However, these symptoms go away within a few hours. Some serious complications may include the following:

• Feeling lightheaded or dizzy
• Excessive bleeding
• Fainting
• Hematoma or accumulation of blood under the skin
• Infection at the puncture site

What Do The Test Results Mean?

The total iron and total iron-binding capacity test results are usually evaluated along with other iron tests. Your abnormal test results can mean the following:

• Iron-Deficiency Anemia

The early stages of iron deficiency are indicated by the slow depletion of your iron stores. It means that there is still enough iron in your body to produce new red blood cells, but the stores are constantly being used up without sufficient reserve. Your serum iron level may be normal at this stage, but the ferritin will always be very low. As the iron deficiency continues in your body, all of the stored iron will be used while your body tries to compensate for it by generating more transferrin to augment the iron transport. Your serum iron level continues to decrease with an upsurge in transferrin and total iron-binding capacity. When this condition progresses, smaller and fewer red blood cells are produced, eventually leading to iron deficiency anemia.

• Iron Overload Or Hereditary Hemochromatosis

If the iron level and transferrin saturation are extremely high and the total iron-binding capacity and ferritin are normal, it can indicate that you have iron poisoning. This condition usually occurs when a hefty dose of iron is consumed all at once (acute) or over time (chronic). Iron poisoning is almost always acute in children and sometimes can be lethal. With iron overload and mutations in the HFE gene, you are susceptible to developing hereditary hemochromatosis. The signs and symptoms include abdominal pain, joint pain, and weakness in their 30s or 40s. Men are more likely to be affected by this condition as compared to women as they lose a major portion of their blood during their menstrual cycles.

Related Tests: Complete Blood Count (CBC), Ferritin Test.

Our clinical experts continually monitor the health and medical content posted on CURA4U, and we update our blogs and articles when new information becomes available. Last reviewed by Dr.Saad Zia on June 05, 2023. 

References

Iron Binding Capacity - StatPearls - NCBI Bookshelf (nih.gov)

NCBI - WWW Error Blocked Diagnostic

Evaluation of iron-binding capacity, amino acid composition, functional properties of Acetes japonicus proteolysate and identification of iron-binding peptides - ScienceDirect

https://www.sciencedirect.com/science/article/abs/pii/S1359511319312048