Iron deficiency (sideropenia or hypoferremia) is one of the most commonly known forms of nutritional deficiencies.

In the human body, iron is present in all cells and has several vital functions—as a carrier of oxygen to the tissues from the lungs in the form of hemoglobin, as a transport medium for electrons within the cells in the form of cytochromes, and as an integral part of enzyme reactions in various tissues. Too little iron can interfere with these vital functions and lead to morbidity and mortality.

The direct consequence of iron deficiency is iron deficiency anemia. Groups that are most prone to developing this disease are children and pre-menopausal women.

Total body iron averages approximately 3.8 g in men and 2.3 g in women. In blood plasma, iron is carried tightly bound to the protein transferrin.

Bacteria, like human cells, require iron for growth, and restricting its bioavailability in this way prevents their infectious growth. Indeed, during fever, one way of controlling bacteria growth is through temporary hypoferremia.

There are several mechanisms that control human iron metabolism and safeguard against iron deficiency. The main regulatory mechanism is situated in the gastrointestinal tract. When loss of iron is not sufficiently compensated by adequate intake after some time that is determined by the state of body iron storage, iron deficiency develops.

Iron-Deficiency Anemia
It is a common, easily treated condition that occurs when you don't have enough iron in your body.

Low iron levels usually are due to blood loss, poor diet, or an inability to absorb enough iron from foods.

Iron-deficiency anemia is a common type. The term "anemia" refers to a condition where your blood has a lower than normal amount of red blood cells. Red blood cells are the ones that carry oxygen and remove carbon dioxide (a waste product) from your body.

Anemia may occur if your red blood cells don’t contain enough hemoglobin. Hemoglobin is an iron-rich protein that aids in carrying oxygen to your body.

Iron-deficiency anemia usually occurs over time if your body doesn’t have enough iron to build healthy red blood cells. Without enough iron, your body starts to use the iron it has stored. Then the stored iron gets used up. When this happens, your body makes fewer red blood cells and the red blood cells made will have less hemoglobin than normal.

Iron-deficiency anemia may cause
fatigue (tiredness),
shortness of breath,
chest pain,
and other symptoms.

Severe iron-deficiency anemia may cause heart problems, infections, problems with growth and development in children, and other complications.
Those at highest risk for iron-deficiency anemia include infants and young children, women, and adults who have internal bleeding.

Iron overload is known as Hemochromatosis

Source:
US Department of Health Services
Sept 2009