Iron deficiency in early childhood in the United States: Risk factors and racial/ethnic disparities

BACKGROUND. Iron deficiency affects 2.4 million US children, and childhood iron-deficiency anemia is associated with behavioral and cognitive delays. Given the detrimental long-term effects and high prevalence of iron deficiency, its prevention in early childhood is an important public health issue. OBJECTIVES. The study objectives were to (1) identify risk factors for iron deficiency in US children 1 to 3 years old, using data from the most recent waves of the National Health and Nutrition Examination Survey IV (1999-2002) and (2) examine risk factors for iron deficiency among Hispanic toddlers, the largest minority group of US children. PATIENTS AND METHODS. Analyses of the National Health and Nutrition Examination Survey IV were performed for a nationally representative sample of US children 1 to 3 years old. Iron-status measures were transferrin saturation, free erythrocyte protoporphyrin, and serum ferritin. Bivariate and multivariable analyses were performed to identify factors associated with iron deficiency. RESULTS. Among 1641 toddlers, 42% were Hispanic, 28% were white, and 25% were black. The iron deficiency prevalence was 12% among Hispanics versus 6% in whites and 6% in blacks. Iron deficiency prevalence was 20% among those with overweight, 8% for those at risk for overweight, and 7% for normal-weight toddlers. Fourteen percent of toddlers with parents interviewed in a non-English language had iron deficiency versus 7% of toddlers with parents interviewed in English. Five percent of toddlers in day care and 10% of the toddlers not in day care had iron deficiency. Hispanic toddlers were significantly more likely than white and black toddlers to be overweight (16% vs 5% vs 4%) and not in day care (70% vs 50% vs 43%). In multivariable analyses, overweight toddlers and those not in day care had higher odds of iron deficiency. CONCLUSIONS. Toddlers who are overweight and not in day care are at high risk for iron deficiency. Hispanic toddlers are more likely than white and black toddlers to be overweight and not in day care. The higher prevalence of these risk factors among Hispanic toddlers may account for their increased prevalence of iron deficiency.