Secular trends in the prevalence of iron deficiency among US toddlers, 1976-2002.

OBJECTIVE: To examine secular trends in iron deficiency among US children 1 to 3 years old. DESIGN: Secular trend analyses of the National Health and Nutrition Examination Survey II-IV. SETTING: Large-scale national survey conducted by the National Center for Health Statistics from 1976 to 2002. PARTICIPANTS: US children 1 to 3 years old. Outcome Measure Prevalence of iron deficiency. RESULTS: Between 1976 and 2002, there was no change in iron deficiency prevalence in US toddlers. Iron deficiency prevalence remained unchanged in Hispanic and white toddlers but decreased among black toddlers. Across all 3 survey waves, racial/ethnic disparities in iron deficiency persisted between Hispanic and white toddlers, with a disparity ratio of at least 2. Iron deficiency prevalence remained high (20%-24%) in overweight toddlers, significantly higher than in those at risk for overweight (11%) and in normal weight or underweight toddlers (8%). Iron deficiency prevalence decreased from 22% to 9% in toddlers in poor households but remained unchanged in toddlers in nonpoor households (7%). In multivariable analyses, Hispanic, younger, and overweight toddlers had higher odds of iron deficiency. CONCLUSIONS: Despite the decline in iron deficiency prevalence among 1-year-old, black, and poor children, iron deficiency prevalence in US toddlers overall has not changed in the last 26 years and remains elevated in certain high-risk groups: Hispanic, younger, and overweight toddlers. Efforts to reduce the prevalence of iron deficiency in infancy and early childhood are urgently needed and should target high-risk groups.

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.