About 75 percent of all the iron in your body is present in hemoglobin, a component of red blood cells. As blood travels to the lungs, the iron in hemoglobin binds to inhaled oxygen molecules and transports them to every cell in your body. In the cells, oxygen helps produce energy that you need for every activity that you carry out. If your diet is deficient in iron, you may experience low energy levels and get easily fatigued due to decreased hemoglobin levels in red blood cells.
Red Blood Cells
Red blood cells are nucleus-free, flexible cells that make up 40 to 45 percent of your total blood volume. Red blood cells deliver oxygen to all the organs and tissues in the body, each one traveling as many as 300 miles during its lifespan of about 120 days, according to Dr. Stanley Schrier, Professor of Medicine at the Stanford University School of Medicine. To ensure an uninterrupted supply of oxygen to the cells, your bone marrow constantly produces hemoglobin-rich red blood cells.
Every red blood cell in your blood is a vehicle for oxygen transport and contains about 250 to 270 million molecules of hemoglobin. The hemoglobin molecule itself consists of a protein component called globin, which is composed of four polypeptide chains. A heme group at the end of each polypeptide chain contains an iron atom, which binds with oxygen and transports it throughout the body. Oxygenated hemoglobin molecules in red blood cells give blood its bright red color.
Symptoms of Iron-Deficiency Anemia
Inadequate supply of oxygen to the cells due to iron deficiency causes symptoms such as pale skin, cold hands and feet, extreme fatigue, weakness, increased heart rate, breathlessness, dizziness, headaches, irritability, inflammation of the tongue and brittle nails. Poor work performance, decreased immunity to infection, slow development in children, complications during pregnancy and restless leg syndrome are also associated with iron deficiency. While severe iron deficiency symptoms may require medical intervention, you can prevent onset of iron deficiency by eating a healthy, well-balanced diet.
Food Sources of iron
Animal foods are the best sources of iron. About 15 to 35 percent of heme iron from beef, chicken, turkey, tuna, crab, shrimp and halibut is easily absorbed. However, only 2 to 20 percent of non-heme iron from plant foods is absorbed. This includes iron in fortified breakfast cereals, oatmeal, pasta, bread, cooked beans, legumes, green vegetables and dried fruits such as raisins and apricots. You can increase absorption of non-heme iron by consuming these foods with vitamin C-rich foods such as fresh fruits, fruit juices and vegetables.
- Office of Dietary Supplements: Iron
- Linus Pauling Institute: Iron
- U.S. Department of Energy: Hemoglobin Functioning
- MayoClinic.com: Iron Deficiency Anemia
- American Society of Hematology: Blood Basics
- Wolters Kluwer health: Red Blood Cell Survival: Normal Values and Measurement
- Palomar College: Blood Components
- Winona State University: Gas Transport
- Comstock Images/Comstock/Getty Images