Iron is a nutrient necessary for the formation of hemoglobin, the protein component of red blood cells. If there is a low amount of iron in the blood, the body is unable to make hemoglobin, which results in a lower red blood cell count. Red blood cells are responsible for carrying oxygen to body tissues and removing carbon dioxide from these tissues. Without an adequate amount of red blood cells, a person can experience fatigue, shortness of breath and pain. This condition is called iron-deficiency anemia. There are several causes of low iron in the blood.
Blood Loss
Blood loss is the most common cause of low levels of blood iron in the United States, according to Mayo Clinic. Because iron is contained in the hemoglobin of the red blood cells, the loss of blood causes a decrease in the amount of iron present. This blood loss may be due to a variety of reasons. In women, heavy menstrual periods are often the cause. Chronic heavy periods can lead to iron-deficiency anemia. Internal bleeding due to peptic ulcers, tumors or colon cancer can also cause low levels of iron in the blood. Sudden trauma, such as a car accident, may also be a reason for a large amount of blood loss.
Lack of Dietary Iron
A diet that is lacking in dietary iron can also cause low levels of iron in the blood. Iron rich foods include meat, poultry, fish, eggs and fortified cereals. Because most iron comes from animal products, vegetarians and vegans often develop iron-deficiency anemia, according to Mayo Clinic. Lack of sufficient iron can also be a problem during times of increased nutrient needs, such as during pregnancy or childhood, according to the National Heart, Lung and Blood Institute. The body requires an increased intake of iron during these times in order to sustain proper growth and development.
Inability to Absorb Iron
The small intestine is responsible for absorbing nutrients into the body. Diseases of the intestines, such as Crohn's disease or celiac disease, or prior intestinal surgery can impair the small intestine's ability to provide iron to the bloodstream. Even if enough iron is being ingested through proper diet, the intestine's decreased ability to absorb iron will result in low levels of iron in the blood. Certain medications, such as antacids, can also cause low levels of iron in the blood. Stomach acid is a vital component to breaking down dietary iron into a form of iron that can utilized by the body. Chronic use of medications that diminish the body's production of stomach acid can cause the development of iron-deficiency anemia, according to Mayo Clinic.
