Variations in Dietary Iron Status May Alter Growth and Cognitive Development




Journal of Nutrition

Related Monographs

Consumer Data: Cognitive Function Iron
Professional Data: Cognitive Function Iron


According to the World Health Organization, iron deficiency is the most common nutritional disorder in the world. There are as many as 4-5 billion people with iron deficiency, approximately 66-80% of the world’s population. Of these, as many as 2 billion people, (over 30% of the world’s population) are considered to be anemic.1

The most common reason for iron deficiency anemia in infants and children is the inadequate or low supply of iron in the diet. Iron, the mineral necessary for the body to manufacture red blood cells, delivers oxygen to all the body’s organs and muscles. The major changes that occur in the body due to an iron deficiency are behavioral, cognitive and psychomotor deficits and decreased immune function. Symptoms include lethargy, irritability, and the inability to concentrate. This causes attention spans to be short which may in turn impair the individual’s ability to learn. Symptoms such as lethargy may hinder the ability to function normally in completing daily tasks.

In a recent study published in The Journal of Nutrition, rats were evaluated to determine the effects of both a dietary iron deficiency and excess iron on physical activity. To determine the effects of early, late and long-term iron deficiency or excess iron (supplementation), rats were fed diets that provided them with specific amounts of iron. The rat’s motor activity was measured at regular intervals and recorded. Both the iron-deficient and iron-supplemented rats showed decreased activity and stereotypic behavior. Iron supplementation did not normalize these variables, showing that the effects of early iron deficiency persisted despite subsequent adequate treatment.

While not a human study, the data collected led the authors of this study to conclude that "iron deficiency in early life leads to irreversible behavioral changes," and that the behavioral changes would not be easy to determine from a biological perspective since the iron therapy reverses the iron lost in the brain.2


1. World Health Organization. Micronutrient deficiencies -Battling iron deficiency anemia. Jul 2001.
2. Piñero DJ, et al. Variations in Dietary Iron Alter Behavior in Developing Rats. Journal of Nutrition. Feb 2001;131:311-318.