Iron Deficiency

Iron (Fe) is a component of hemoglobin, myoglobin, and many enzymes in the body. Heme iron is contained mainly in animal products. It is absorbed much better than nonheme iron (eg, in plants and grains). Nonheme iron accounts for > 85% of iron in the average diet. However, absorption of nonheme iron is increased when it is consumed with animal protein and vitamin C.

(See also Overview of Mineral Deficiency and Toxicity Overview of Minerals Six macrominerals are required by people in gram amounts. Four cations: Sodium, potassium, calcium, and magnesium Two accompanying anions: Chloride and phosphorus Daily requirements range from... read more .)

Iron deficiency is one of the most common mineral deficiencies in the world. It may result from the following:

Chronic bleeding due to colon cancer is a serious cause in middle-aged and older people.

Iron deficiency and iron deficiency anemia Iron Deficiency Anemia Iron deficiency is the most common cause of anemia and usually results from blood loss; malabsorption, such as with celiac disease, is a much less common cause. Symptoms are usually nonspecific... read more are common among elite runners and triathlon athletes (1 General reference Iron (Fe) is a component of hemoglobin, myoglobin, and many enzymes in the body. Heme iron is contained mainly in animal products. It is absorbed much better than nonheme iron (eg, in plants... read more ).

When deficiency is advanced, microcytic anemia Iron Deficiency Anemia Iron deficiency is the most common cause of anemia and usually results from blood loss; malabsorption, such as with celiac disease, is a much less common cause. Symptoms are usually nonspecific... read more develops.

In addition to anemia, iron deficiency may cause pica Pica Pica is persistent eating of nonnutritive, nonfood material for ≥1 month when it is developmentally inappropriate (eg, pica is not diagnosed in children < 2 years) and when it is not part... read more (a craving for nonfoods) and spoon nails and is associated with restless leg syndrome Periodic Limb Movement Disorder (PLMD) and Restless Legs Syndrome (RLS) Periodic limb movement disorder (PLMD) and restless legs syndrome (RLS) are characterized by abnormal motions of and, for RLS, usually sensations in the lower or upper extremities, which may... read more . Rarely, iron deficiency causes dysphagia Dysphagia Dysphagia is difficulty swallowing. The condition results from impeded transport of liquids, solids, or both from the pharynx to the stomach. Dysphagia should not be confused with globus sensation... read more due to postcricoid esophageal web.

Diagnosis of iron deficiency involves complete blood count, serum ferritin and iron levels, and possibly measurement of transferrin saturation (iron-binding capacity). In deficiency states, iron and ferritin levels tend to be low, and iron-binding capacity tends to be high.

Rarely, when the diagnosis of iron deficiency remains uncertain, examination of bone marrow for iron may be necessary.

Treatment of iron deficiency involves correcting the cause if possible (eg, treatment of a bleeding intestinal tumor). All people with moderate or severe iron deficiency and some people with mild deficiency require iron supplementation Treatment Iron deficiency is the most common cause of anemia and usually results from blood loss; malabsorption, such as with celiac disease, is a much less common cause. Symptoms are usually nonspecific... read more .