Function In Our Bodies

Iron is an essential component of hemoglobin, an erythrocyte protein that transfers oxygen from the lungs to the tissues. As a component of myoglobin, a protein that provides oxygen to muscles, iron supports metabolism. Iron is also necessary for growth, development, normal cellular functioning, and synthesis of some hormones and connective tissue.

Examples Of Iron

The richest sources of heme iron in the diet include lean meat and seafood . Dietary sources of nonheme iron include nuts, beans, vegetables, and fortified grain products. In the United States, about half of dietary iron comes from bread, cereal, and other grain products. Breast milk contains highly bioavailable iron but in amounts that are not sufficient to meet the needs of infants older than 4 to 6 months.

Physcial Condition/disease caused by deficiency

Iron depletion and deficiency progresses through several stages

  1. Mild deficiency or storage iron depletion: Serum ferritin concentrations and levels of iron in bone marrow decrease.
  2. Marginal deficiency, mild functional deficiency, or iron-deficient erythropoiesis (erythrocyte production): Iron stores are depleted, iron supply to erythropoietic cells and transferrin saturation decline, but hemoglobin levels are usually within the normal range. In addition, plasma iron levels decline and plasma transferrin concentrations (measured by plasma total iron-binding capacity) rise, resulting in decreased transferrin saturation. Serum transferrin receptor concentrations also increase.
  3. IDA: Iron stores are exhausted; hematocrit and levels of hemoglobin decline; and the resulting microcytic, hypochromic anemia is characterized by small red blood cells with low hemoglobin concentrations.