Major surgery imposes extraordinary demands on your body. Your underlying condition creates stresses that surpass those of normal daily living. Once you enter the hospital, your immune system is confronted by infectious organisms that you would not ordinarily encounter. Anesthetic agents challenge your liver, kidneys, heart and lungs. The tissue injury resulting from the procedure itself provokes your immune system further and increases your need for nutrients that permit optimal healing. And, if you lose a significant amount of blood, you might need additional iron or even a transfusion.
Iron
Iron is a metallic mineral that your body needs to produce hemoglobin, the oxygen-carrying protein in your red blood cells. Iron is also required for the synthesis of myoglobin, which is a hemoglobin-like molecule found in your muscle cells. Iron serves as a cofactor for an important complex of liver and intestinal enzymes called cytochromes, and it supports wound healing and normal immune function. About 25 percent of your total body iron is held in storage. If your iron stores are low, you can become anemic, you may not heal properly and you become more susceptible to infection.
Blood Loss
Whenever you lose blood, you also lose iron. One unit of blood contains about 200 mg of iron. Some surgeries cause greater blood loss than others. Orthopedic procedures, such as knee or hip replacements, are inherently "bloody." In fact, your doctor may have you donate several units of your own blood during the weeks before such surgeries, so you can be transfused if necessary. Occasionally, surgical complications lead to more bleeding than is customary for a given procedure. If you receive a transfusion, your iron stores will be at least partially replenished, but you may need additional iron to return those stores to normal levels.
Iron Overload
According to Dr. Elson Haas, author of "Staying Healthy with Nutrition," your body recycles iron very efficiently, and a healthy adult male loses only about 1 mg each day. Greater losses occur in women during menstruation, and pregnancy and nursing increase iron requirements. Any other source of blood loss, such as gastrointestinal bleeding or surgery, also increases your iron needs. However, if you consume more iron than you need, the excess can damage your liver, kidneys, brain, joints, heart and gonads. "The Merck Manual of Diagnosis and Therapy" reports that the average American diet furnishes enough iron to maintain iron stores for most healthy people.
Considerations and Recommendations
Surgery is not an uncommon cause of blood and iron loss, but most people, particularly men, maintain iron stores that prevent anemia unless blood loss is significant. Your doctor should be able to tell you whether you lost enough blood during your surgery to merit iron supplementation. A blood test called a serum ferritin, performed a few days after your surgery, can help to determine whether your iron stores are low. Due to the risk for iron overload, you should not take additional iron without your physician's advice.
References
- "Staying Healthy with Nutrition: Iron"; Elson M. Haas, M.D.; 2006
- "The Merck Manual of Diagnosis and Therapy, 18th Edition: Iron Deficiency Anemia"; Mark H. Beers, M.D., Editor-in-Chief; 2006
