Chapter 9 IRON DEFICIENCY ANEMIA
Irene Alton
Iron deficiency is the most prevalent nutritional deficiency and the most common cause of anemia in the United States.1 Iron deficiency anemia is characterized by a defect in hemoglobin synthesis, resulting in red blood cells that are abnormally small (microcytic) and contain a decreased amount of hemoglobin (hypochromic).2 The capacity of the blood to deliver oxygen to body cells and tissues is thus reduced. According to the third National Health and Nutrition Examination Survey (NHANES III) data, iron deficiency, defined by two or more abnormal measurements (serum ferritin, transferrin saturation and/or erythrocyte protoporphyrin), continues to be relatively prevalent in U.S. females, affecting 7.8 million adolescents and women of childbearing age.3 Iron deficiency anemia, a more severe stage of iron deficiency (defined as a low hemoglobin in combination with iron deficiency), was found in 3.3 million females.3 The prevalence of iron deficiency and anemia in adolescent males and females, based on the 5th percentile, NHANES III data, is listed in Table 1.
TABLE 1 Prevalence of Iron Deficiency and Iron Deficiency Anemia in Adolescent Males and Nonpregnant Females Gender/Age (yrs) Females 12-15 16-19 Males 12-15 16-19 1% <1% <1% <1% Iron Deficiency 9% 11% Iron Deficiency Anemia 2% 3%
Source: Centers for Disease Control and Prevention. Recommendations to prevent and control iron deficiency anemia in the United States. Morb Mortal Wkly Rep 1998; 47:1-29.
A two to three times higher prevalence of iron deficiency was found in Mexican-American, compared to white, non-Hispanic adolescent females.4 Higher rates were also noted in other minority and low income populations.3 SIGNIFICANCE Iron is essential to all cells. Functions of iron include involvement in energy metabolism, gene regulation, cell growth and differentiation, oxygen binding and transport, muscle oxygen use and storage, enzyme reactions, neurotransmitter...