Total Iron Binding Capacity (TIBC)

July 21, 2020

What is total iron binding capacity (TIBC)?

Total Iron Binding Capacity (TIBC) measure how well the blood and iron bind to each other. It can be used alongside other iron tests to help diagnose iron deficiency or if there is too much iron in the body.[1]

Why take a TIBC blood test?

A total iron-binding capacity test measures the ability of the blood to bind to and transport iron around the body. The test is like a transferrin test and you will usually have one or the other. The TIBC test analyses how much transferrin is available in the blood to bind to iron.

You can test your iron levels by purchasing a simple at-home finger prick test kit which is then analysed at an accredited lab. Forth offers a number of blood tests which include iron markers such as our best-selling Baseline Plus health check or our Nutri-check test.  A total iron binding capacity blood test is also available in some of our bigger blood test profiles such as Vitality which tests over 30 biomarkers integral to good health.

What function does TIBC have in the body?

Because a TIBC test shows how much transferrin is available to bind to iron in the blood, the test is like a transferrin test.

Transferrin is a glycoprotein produced in the liver whose main function is in iron metabolism and transporting iron around the body via the blood to various tissues.[2] The levels of transferrin increase or decrease depending on iron status. Because transferrin is made in the liver, if the level is low it can signify liver disease.

How do changes in TIBC affect health and wellbeing?

Changes in transferrin levels in the blood can indicate iron-related conditions. For example, an increased transferrin level is often seen in cases of iron deficiency, anaemia and pregnancy. If plasma transferrin levels rise then this causes a decrease in transferrin iron saturation, which together causes an increase in total iron binding capacity in states of iron deficiency.

A reduced transferrin level in the plasma is seen in diseases which cause iron overload.

If you are worried about your iron levels or just want to check where you fall on the range, you can test your iron levels with Forth’s leading blood test service.

What can cause TIBC to change?

Iron deficiency causes increases in TIBC and transferrin levels. Iron deficiency can be caused by malnutrition where physiological requirements are unable to be met by iron absorption from the diet.[3] Therefore, if we do not consume enough iron in our diet, then we are at risk of becoming deficient. There are two types of iron, haem and non-haem. Haem iron comes from animal sources and non-haem from plant sources. Individuals who follow plant-based diets are at an increased risk of iron deficiency because less than 10% of non-haem iron is absorbed.[3]

Low transferrin and TIBC levels are caused by chronic diseases or haemochromatosis. Haemochromatosis is also known as iron overload and is caused by several medical conditions, commonly an inherited disorder.

Genetic haemochromatosis is caused by a faulty gene which increases the amount of iron entering the body.[4] Individuals with haemochromatosis absorb twice as much iron as normal which is toxic for the body and can be life-threatening.

What Are The most common symptoms of low or high iron?

The common symptoms of iron deficiency anaemia are:

  • Tiredness and a lack of energy
  • Shortness of breath
  • Pale skin
  • Heart palpitations[5]

Haemochromatosis causes symptoms, like:

  • Fatigue and a lack of energy
  • Weakness in the limbs
  • Joint pain
  • Stomach pain
  • Loss of sex drive
  • Liver damage
  • Type II diabetes
  • Impotence or early menopause
  • Jaundice

How to keep TIBC in the healthy range

Iron is essential for red blood cell health. A good source of iron is red meat and liver. It is recommended that red meat is consumed once per week to help keep iron levels within normal parameters. Women who are of menstruating age need to keep their iron intake increased, particularly around the time of their periods. Individuals who follow a vegan or vegetarian diet will need to get their iron from plant-based sources.

Good food sources of iron are:

  • red meat
  • liver
  • green leafy vegetables e.g. spinach
  • dried fruit
  • pulses
  • nuts seeds

The absorption of iron from plant-based sources is better when vitamin C is present. [6]For example, fortified breakfast cereals paired with a glass of orange juice. Tea can affect the absorption of iron, so you should refrain from drinking tea with your meals and switch to drinking it between meals. [7]

It is possible to get all the iron you need from a varied and balanced diet. Therefore, there should be no need to take iron supplements. However, a doctor may recommend supplements if your iron levels are considerably low.

Iron levels can be influenced by too much or too little exercise. Not having enough iron can affect your muscles ability to recover following exercise.

If you have haemochromatosis, you may need a genetic test to determine whether you carry a genetic mutation which causes the disease. There are some lifestyle choices you can make to help control your iron intake if you experience iron overload.

You should avoid:

  • iron supplements or vitamins containing iron
  • fortified breakfast cereals
  • shellfish
  • you may need to cut down on your consumption of red meat and other animal foods as these are rich in iron

Drinking alcohol can speed up and worsen the impact of haemochromatosis and if you already have liver cirrhosis you should avoid alcohol completely.


[1] Lab Tests Online UK. (2014). TIBC, UIBC ad Transferrin. Available at:

[2] Ogun AS, Adeyinka A. (2016). Biochemistry, Transferrin. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing. Available from:

[3] Zimmerman, M, B and Hurrell, R, F. (2007). Nutritional Iron Deficiency. Lancet: 370, pp 511-520.

[4] British Liver Trust. (2019). Haemochromatosis. Available at:

[5] NHS. (2018). Iron Deficiency Anaemia. Available at:

[6] Lane, D, J, R and Richardson, D, R. (2014). The Active Role of Vitamin C in Mammalian Iron Metabolism: Much More than Just Enhanced Iron Absorption. Free Radical Biology and Medicine: 75, pp 69-83.

[7] Zijp, I, M., Korver, O and Tijburg, L, B, M. (2000). Effect of Tea and Other Dietary Factors on Iron Absorption. Critical Reviews in Food Science and Nutrition: 40(5), pp 371-398.

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This information has been medically reviewed by Dr Nicky Keay

Nicola has extensive clinical and research experience in the fields of endocrinology and sport and exercise medicine. Nicky is a member of the Royal College of Physicians, Honorary Fellow in the Department of Sport and Exercise Sciences at Durham University and former Research Fellow at St. Thomas' Hospital.

Dr Nicky Keay

Dr Nicky Keay

BA, MA (Cantab), MB, BChir, MRCP.