Iron is one of the most important minerals in the human body. It is also one of the most abundant minerals on the planet. Iron is essential for many of the body’s metabolic functions, but its main role is in the production of hemoglobin, the protein within red blood cells that binds oxygen for delivery to the various organs 2. Iron is also important in the production of myoglobin, which helps catch oxygen for our muscles.

Production of hemoglobin

Iron is an integral component of hemoglobin, the oxygen-binding molecule inside red blood cells. As matter of fact, the iron within red blood cells is what gives blood its color. According to the University of California San Francisco Medical Center, about 70 percent of the body’s iron stores within red blood cells and the hemoglobin molecule 2. Iron is within a molecular complex known as the heme group. Each hemoglobin protein can carry four oxygen molecules to the tissues, and then releases it for the cells to carry out their metabolic processes.

Production of myoglobin

Normal Range for Iron in Blood

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Myoglobin is another oxygen-binding protein, mostly found in skeletal muscle and the heart. According to Lab Tests Online, myoglobin’s job is to trap oxygen within muscle cells for use in the metabolic processes that generate energy for muscle contraction 1. The presence of iron in muscles gives them their rich brown appearance. Just like hemoglobin, myoglobin has a heme group at its core, where it binds and stores oxygen, ready for use in energy generation.

Other roles of iron

Iron is also important in other metabolic processes. According to Washington University, the synthesis of DNA, the basic building block of all cells in the body, requires iron. Iron is also a component of neurotransmitters, the substances used by brain cells to communicate with each other. Iron is part of the production process of connective tissue, the cells and fibrous tissue that forms the “cellular glue” of the body. Iron is also important in the health of the body’s immune system.

Iron deficiency

How Is Iron in the Blood Measured?

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Iron deficiency results either from poor dietary intake of iron, the inability to absorb iron from the digestive tract, or from excessive loss, such as in heavy menstrual bleeding. Because the majority of iron goes into the production of red blood cells, iron deficiency results in anemia. Iron deficiency anemia causes microcytic anemia, in which the body produces fewer and smaller red blood cells, which decreases their capacity to transport oxygen. Symptoms of iron deficiency anemia include weakness, fatigue and paleness.