How to interpret your iron status

Interpreting your iron blood tests

Serum iron actually only represents about 0.1% of the iron in your body, and it typically is just an artifact of the last few meals you have eaten. Serum iron will increase after a meal, and decrease throughout the day. Serum iron will be higher in the morning than in the afternoon, and higher after a meal or an iron supplement.

Iron is bound to a transfer protein called Transferrin. Each molecule of transferrin contains 2 atoms of iron. Transferrin is made by the liver to transfer iron around the body. The transferrin molecule is constantly traveling around the bloodstream and bringing iron to the tissues. Low transferrin means for some reason the body has decided to keep iron in storage. Higher levels of transferrin mean there is a demand for iron in the body, and the liver has sent out transferrin to deliver the package! High transferrin can mean that the body is in need of iron, which could be due to iron deficiency, or simply high iron utilization, such as during pregnancy.

You may also see transferrin saturation on an iron panel. That is simply an indication of how much iron the transferrin is carrying. If saturation is low it could indicate a deficiency in iron, but it will decrease as the day progresses, and below in the afternoon. High saturation may simply be due to the ingestion of iron prior to the blood test but is also seen in cases of hepatitis.

Ferritin is the storage form of iron, and each molecule can contain about 4,500 atoms of iron! Serum ferritin does not have any iron in it, rather that is ferritin that has “leaked” into the blood when we are producing ferritin. It is referred to as apoferritin. However, it is a reflection of how much ferritin we are producing. Low ferritin is the strongest indicator that you are lacking iron, as it indicates you do not have iron storage. High levels COULD suggest you have too much iron. However, when there is inflammation in the body, transferrin production decreases, and the storage of iron in ferritin increases to contain the iron in storage. The reason for this is that bacteria and other inflammatory compounds can use iron to proliferate and worsen inflammation, therefore when inflammation is detected iron is “sucked up” into storage to keep it out of the bloodstream. There are a few scenarios you may have.

• High ferritin but low transferrin is indicative that there is inflammation occurring somewhere in your body. That inflammation could be due to an injury, infection, or disease.

• Low Ferritin but high transferrin is indicative of an iron deficiency, and the body is doing its best to get what little iron is in your body out to the rest of the body.

• High ferritin and high transferrin are almost always a sign of an iron overload

• Low iron and low transferrin saturation, but normal ferritin and transferrin are almost always caused by taking the sample late in the day, without eating any iron-rich food prior.

• Normal iron and transferrin saturation and transferrin, but low ferritin would be a sign you are iron deficient but consumed iron prior to the test.