What Is a Total Iron Binding
Capacity (TIBC) Test?
A total iron binding capacity (TIBC) test is a type of blood test that
gauges whether there’s too much or too little iron in your bloodstream.
Iron is a type of mineral found in all of the body’s cells. You get the
iron you need through your diet. Once iron enters the body, it’s carried
throughout your bloodstream by a protein called transferrin, which is produced by
your liver. The TIBC test evaluates how well transferrin carries iron through
In your blood, iron helps form hemoglobin. Hemoglobin is an important
protein in red blood cells that helps carry oxygen throughout the body so it
can function normally. Iron is considered an essential mineral because
hemoglobin can’t be made without it.
Iron can be found in numerous different foods, including:
- dark green, leafy
vegetables, such spinach
- whole grains
Daily Iron Recommendations
The Food and Nutrition
Board at the Institute of Medicine recommends people consume certain amounts
of iron each day. For healthy people, it recommends the following amounts:
Infants and Children
- 6 months old or
younger: 0.27 milligrams per day (mg/day)
- 7 months old to age
1: 11 mg/day
- ages 1 to 3: 7
- ages 4 to 8: 10
- ages 9 to 13: 8
- ages 14 to 18: 11
- ages 19 or older: 8
- ages 9 to 13: 8
- ages 14 to 18: 15
- ages 19 to 50: 18
- ages 51 or older: 8
- lactating women
ages 19 to 30 year: 9 mg/day
The Centers for Disease Control and Prevention recommends that pregnant
females of all ages take 30 mg/day. Pregnant and lactating women may need
different amounts of iron than those recommended. Check with your doctor to
find out how much you need.
Why a Total Iron Binding Capacity
Test Is Performed
Doctors typically order TIBC tests to check for medical conditions that
cause abnormal iron levels.
Your doctor may perform a TIBC test if you’re experiencing the symptoms
of anemia, or a lack of iron in the blood. In the United States, iron is the
most common type of dietary deficiency. Iron deficiency is usually the cause of
anemia, but the condition may also be triggered by increased blood loss during
menstruation, pregnancy, and chronic infections.
The symptoms of low iron levels include:
- feeling tired and
- skin pallor
- an increase in
- always feeling cold
- a swollen tongue
- difficulty concentrating
at school or work
- delayed mental
development in children
A TIBC test may also be ordered if your doctor suspects you have too
much iron in your blood. High levels of iron most commonly indicate an
underlying medical condition. Some common causes of high iron levels include:
In rare cases, high iron levels may be caused by an overdose of vitamins
or iron supplements.
The symptoms of high iron levels include:
- feeling tired and
- painful joints
- a change in skin
color to bronze or gray
- abdominal pain
- sudden weight loss
- a low sex drive
- hair loss
- an irregular heart
Call your doctor if you’re experiencing the symptoms of low or high iron
levels. If any underlying conditions are left untreated, you’re at an increased
for serious complications, such as:
- liver disease
- a heart attack
- heart failure
- bone problems
- metabolic issues
- hormone disorders
How to Prepare for a Total Iron
Binding Capacity Test
Fasting is required for a TIBC test to ensure the most accurate results.
This means you shouldn’t eat or drink anything for at least eight hours before
Some medications can also affect the results of a TIBC test, so it’s
important to tell your doctor about any prescription or over-the-counter
medications you’re taking. Your doctor may tell you to stop taking certain
medications before the test. However, you shouldn’t stop taking any medications
without talking to your doctor first.
Some medications that can affect the test results include:
- birth control pills
How a Total Iron Binding Capacity
Test Is Performed
A TIBC test may be ordered along with a serum iron test, which measures
the amount of iron in your blood. Together, these tests can help determine
whether there’s an abnormal amount of iron in your blood.
The tests involve taking a small sample of blood. Blood is usually drawn
from a vein or artery in the hand or the bend of the elbow. The following steps
- A healthcare provider will first clean the area with an
antiseptic and then tie an elastic band around your arm. This will make your
veins swell with blood.
- Once they find a vein, they’ll insert the needle. You can
expect to feel a slight prick or stinging sensation when the needle goes in.
However, the test itself isn’t painful.
- They’ll only collect enough blood as needed to perform the
test and any other blood tests your doctor may have ordered.
- After enough blood has been drawn, they’ll remove the needle
and place a bandage over the puncture site. They’ll tell you to apply pressure
to the area with your hand for a few minutes.
- The blood sample will then be sent to a laboratory for
- Your doctor will follow up with you to discuss the results.
Risks of a Total Iron Binding
Blood tests carry few risks. Some people have a slight bruise or
experience soreness around the area where the needle was inserted. However,
this usually goes away within a few days.
Complications from blood tests are rare, but they can occur. Such
- excessive bleeding
- fainting or
- blood accumulating
under the skin, or a hematoma
- infection at the
Total Iron Binding Capacity Test
Normal values for the TIBC test can vary among laboratories. However, most
laboratories define a normal range as 240 to 450 micrograms per deciliter (mcg/dL).
A total iron binding capacity value above 450 mcg/dL usually means that
there’s a low level of iron in your blood. This may be caused by a lack of iron
in the diet, increased blood loss during menstruation, pregnancy, or a chronic
A total iron binding capacity value below 240 mcg/dL usually means that
there’s a high level of iron in your blood. This may be caused by:
- liver damage
- iron or lead
- frequent blood
- hemolytic anemia, which is a
condition that causes red blood cells to die prematurely
- sickle cell anemia, which is an
inherited condition that causes red blood cells to change shape
- hemochromatosis, which is a genetic
condition that causes a buildup of iron in the body
Your doctor will explain what your individual results mean for you and
what the next steps should be.