Iron deficiency is a lack of iron in the cells which can interfere with the ability of cells to carry oxygen to tissues, transport electrons, and complicate enzyme reactions.

Lack of iron can lead to iron deficiency anemia, a condition where the body's stores of iron have been depleted, affecting the production of red blood cells. During pregnancy, lack of iron can increase the risk for giving birth to preterm babies, In infants, iron deficiency can delay motor and mental functions.

Iron deficiency can be treated with iron supplements and diet.