Transferrin is made in the liver and is the major protein in the blood which binds to iron and transports it round the body. This test measures how much this protein is 'saturated' by iron.
What might a low result mean?
Low transferrin saturation levels can indicate iron deficiency as it means that very little of the transferrin is saturated with iron. Iron deficiency can be caused by blood loss (gastrointestinal bleeding or menstruation), lack of dietary iron, or pregnancy. Inflammatory bowel conditions can also cause low iron through malabsorption.
What might a high result mean?
High transferrin saturation levels can indicate iron overload (hereditary haemochromatosis) as it means that a high proportion of your transferrin is saturated with iron.