Healthy adults have total iron of approximately 4 g for men and 2.5 g for women.1 While most of this iron is contained in the hemoglobin of your red blood cells, iron storage sites also contain approximately 1 g in men and 0.3 g in women.2
In addition to the iron you use each day, you typically lose about 1 mg or more, so it’s important to make sure you eat enough iron-rich foods to give your body the iron it needs.1,2 About 1 mg of iron is lost daily in the stool from sloughed ferritin-containing intestinal lining cells called enterocytes. Some iron is also lost from sloughed skin cells. An average additional 1 mg of iron is lost daily from menstruation in women. Bleeding from other causes further increases iron loss.
Under normal circumstances, you might absorb 5% to 10% of the iron in your food.2 However, your body will automatically decrease absorption if you have enough iron stored away. And, if you don’t have enough iron stores, your body will increase absorption.2,3
1 Centers for Disease Control and Prevention. Recommendations to prevent and control iron deficiency in the United States. MMWR Recomm Rep. 1998;47(RR-3):1-36. http://www.cdc.gov/MMWR/preview/mmwrhtml/00051880.htm. Accessed April 2, 2013.
2 Barton JC. Iron deficiency. In: Rakel RE, Bope ET, eds. Conn’s Current Therapy. Amsterdam, the Netherlands: Saunders/Elsevier; 2008:385-389.
3 Finch CA, Cook JD. Iron deficiency. Am J Clin Nutr. 1984;39(3):471-477.