At a Glance Why Get Tested? To determine your body's total iron
storage capacity When to Get Tested? When your doctor suspects
that you may have too little or too much iron in your system A
blood sample drawn from a vein in your arm Test Preparation
Needed? You may be instructed to fast for 12 hours before the
test; in this case, only water is permitted. The Test Sample
What is being tested? This test measures the amount of ferritin
in the blood. Ferritin is an iron-containing protein that is the
primary form of iron stored inside of cells. The small quantity
of ferritin that is released into the blood is a reflection of
the amount of total iron stored in the body. In healthy people,
about 70% of the iron absorbed by the body is incorporated into
the hemoglobin of red blood cells. Most of the remaining 30% is
stored as ferritin or as hemosiderin, a complex of iron,
proteins, and other materials. Ferritin and hemosiderin are
present primarily in the liver but also in the bone marrow,
spleen, and skeletal muscl