Transferrin Saturation Test

The transferrin saturation test is a sensitive and relatively inexpensive biochemical measure of iron overloading.

Colds, inflammation, liver disease, and malignancies can falsely lower test values.

Function

Transferrin is a blood protein that picks up iron absorbed by the intestines and transports it from one location to another.  When iron absorption is abnormally high, transferrin proteins become more saturated with iron.  An elevated test value therefore reflects an increase in iron absorption.

Instructions

Several factors can falsely elevate test values, including the use of vitamin C, dietary supplements containing iron, medicinal iron, and estrogen preparations.  Patients should avoid these products for 24 hours prior to the fasting blood draw.  The placebos contained in some oral contraceptive packages may contain iron.  These iron-containing placebos should be avoided for 24 hours prior to the fasting blood draw.