Iron deficiency is one of the most common known nutritional deficiencies worldwide, according to the Centers for Disease Control and Prevention (CDC). Its prevalence is highest among young children and women of childbearing age (particularly pregnant women).

In infants and children, iron deficiency causes developmental delays and behavioral disturbances. These developmental delays may persist into the child’s school age if the iron deficiency is not fully reversed.

In pregnant women, iron deficiency anemia during the first two trimesters of pregnancy is associated with a twofold increased risk for a preterm delivery, and a three-fold increased risk for delivering a low-birth-weight baby. Both of these conditions (prematurity and low birth weight) are closely associated with mental retardation of newborns.

In the United States, iron deficiency affects 700,000 children aged 1 to 2 years, and 7.8 million adolescent girls and women of childbearing age, according to the CDC.

In the human body, iron is present in all cells and has several vital functions. It is known to be a carrier of oxygen from the lungs to the tissues; it facilitates oxygen use in the muscles; it is a transport medium for electrons within the cells; and it is an integral part of enzyme reactions in various tissues. Too little iron can interfere with these vital functions, and in severe cases can lead to death or permanent damage.

In the United States, the prevalence of iron deficiency anemia among children declined during the 1970s. This is associated with increased iron intake during infancy. In contrast, the rate of anemia among low-income women during pregnancy is high, and no improvement has been noted since the 1970s.

(Recommendations to Prevent and Control Iron Deficiency in the United States: Recommendations and Reports, CDC, April 3, 1998)