Nestled within hemoglobin in red blood cells, iron atoms bind oxygen, and shuttle it from the lungs to cells throughout the body.
Many enzymes also use iron to extract energy for cell processes.
According to United Nations statistics, 1.3 billion people throughout the world are iron deficient. Scientists have known for decades that iron deficiency causes fatigue and low productivity. Severe forms of anemia can even lead to cardiac arrest. In studies in Shanghai and Nepal, Stoltzfus, assistant professor of international health, found that anemia appears to increase a pregnant woman's risk of premature delivery and of having an underweight baby. Researchers have also discovered that iron deficiency impairs cognitive development.