If you are feeling rundown, having difficulty concentrating and seem to be getting sick more often than usual, you may be iron deficient. Iron is an essential mineral necessary for the transportation of oxygen throughout your body. Iron is also needed to support cell growth and development. Up to 80 percent of the world's population is iron deficient, according to the Office of Dietary Supplements. There are a number of blood markers your doctor will use in addition to your blood's iron count to diagnose iron-deficiency anemia.
Complete Blood Count
The complete blood count, also known as the CBC, is usually the first test a doctor will order when testing iron status in your blood. This test measures your hemoglobin, hematocrit and mean corpuscular volume. Hemoglobin is the protein that requires iron to transport oxygen in your body. Low levels of hemoglobin may indicate low iron levels. A normal hemoglobin test measures 13.5 to 17.5 grams of hemoglobin per deciliter, g/dL, of blood for men, and 12.0 to 15.5 g/dL for women. Hematocrit measures the percentage of red blood cells in your total blood volume; the normal range is 34.9 to 44.5 percent for adult women, and 38.8 to 50 percent for adult men. Mean corpuscular volume, or MCV, measures the size of the cells. A low MCV may indicate low iron levels. Normal MCV is 80 to 100 femtoliter.
Serum Iron
A serum iron test will only be ordered following abnormal results of the CBC. The total iron binding capacity, or TIBC, is also tested at the same time. The TIBC measures how much iron is being transported in the blood. For best results, you should fast for 12 hours before testing for serum iron. Normal serum iron levels should be 115 micrograms per 100 milliliters, or mcg/100 mL, plus or minus 50 mcg/100 mL. A normal TIBC is 330 mcg/100 mL, plus or minus 30 mcg/mL. Low serum iron levels and high a TIBC are indicative of iron deficiency.
Ferritin
Ferritin is the storage form of iron. Measuring your ferritin level indicates how much of your stored iron you are using. A normal ferritin level ranges from 40 to 160 mcg/L. If your ferritin levels are low, you may be iron deficient.
Transferrin Saturation
Transferrin saturation measures the iron supplied to your tissues. It is measured as a percentage and determined by dividing the serum iron by the TIBC. A normal transferring saturation ranges from 20 to 50 percent. A low transferrin saturation is another indicator of iron deficiency.
References
- "Krause's Food, Nutrition and Diet Therapy"; L. Kathleen Mahan, Sylvia Escott-Stump; 1996
- MayoClinic.com; Iron deficiency anemia: Tests and diagnosis; March 2011
- Office of Dietary Supplements; Iron; August 2007
- MedlinePlus; RBC indices; David C. Dugdale, III, M.D.; February 2010
- Lab Tests Online; Iron; October 2009
