In women of childbearing age, heavy menstrual periods can be a source of blood loss causing iron-deficiency anemia. People who do not consume much iron in their diet, such as vegans or vegetarians, are also at increased risk of developing iron deficiency anemia. Parasitic disease
The leading cause of iron-deficiency anemia worldwide is a parasitic disease known as a helminthiasis caused by infestation with parasitic worms (helminths); specifically, hookworms. The hookworms most commonly responsible for causing iron-deficiency anemia include Ancylostoma duodenale, Ancylostoma ceylanicum, and Necator americanus. The World Health Organization estimates that approximately two billion people are infected with soil-transmitted helminths worldwide. Parasitic worms cause both inflammation and chronic blood loss by binding to a humans small-intestinal mucosa, and through their means of feeding and degradation, they can ultimately cause iron-deficiency anemia. Blood loss
Red blood cells contain iron, so blood loss also leads to a loss of iron. There are several causes of blood loss including menstrual bleeding, gastrointestinal bleeding, stomach ulcers, and bleeding disorders. The bleeding may occur quickly or slowly. Slow, chronic blood loss within the body — such as from a peptic ulcer, angiodysplasia, inflammatory bowel disease, a colon polyp or gastrointestinal cancer (e.g., colon cancer)— can cause iron-deficiency anemia. Menstrual bleeding
Menstrual bleeding is a common cause of iron deficiency anemia in women of child-bearing age. Women with menorrhagia (heavy menstrual periods) are at risk of iron-deficiency anemia because they are at higher-than-normal risk of losing a larger amount blood during menstruation than is replaced in their diet.
Most women lose about 40 mL of blood per cycle. Iron is lost with the blood. Some birth control methods, such as pills and IUDs, may decrease the amount of blood, therefore iron lost during a menstrual cycle. Intermittent iron supplementation may be as effective a treatment in these cases as daily supplements and reduce some of the adverse effects of long term daily supplements. Gastrointestinal bleeding
The most common cause of iron deficiency anemia in men and post-menopausal women is gastrointestinal bleeding. There are many sources of gastrointestinal tract bleeding including the stomach, esophagus, small intestine, and the large intestine (colon). Gastrointestinal bleeding can result from regular use of some groups of medication, such as non-steroidal anti-inflammatory drugs (e.g. aspirin), as well as antiplatelets such as clopidogrel and anticoagulants such as warfarin; however, these are required in some patients, especially those with states causing a tendency to form blood clots. Colon cancer is another potential cause gastrointestinal bleeding, thus iron deficiency anemia. Typically colon cancer occurs in older individuals. In addition, some bleeding disorders can cause gastrointestinal bleeding. Two examples of bleeding disorders are von Willebrand disease and polycythemia vera. Diet
The body normally gets the iron it requires from foods. If a person consumes too little iron, or iron that is poorly absorbed (non-heme iron), they can become iron deficient over time. Examples of iron-rich foods include meat, eggs, leafy green vegetables and iron-fortified foods. For proper growth and development, infants and children need iron from their diet.