High prevalence of iron deficiency in an urban low-income infant/toddler population

Background: Both iron deficiency anemia (ID) and ID without anemia (IDA) in early life may have lasting neurodevelopmental consequences. Current NHANES data indicate a 9.2% prevalence of ID in U.S. children aged 12 - 35 months, with no poverty or Black/White race differential. Abnormal zinc protoporphyrin (ZPP) has been shown to be highly specific for ID in the absence of elevated lead (Pb). Objective: to determine the prevalence of abnormal ZPP in a large urban low-income infant/toddler population Methods: We reviewed initial routine screening data from all children age 8-18 months in primary care at Boston Medical Center between 1/1/02 and 12/31/10. Children with Pb >10mcg/dL and those with a sickle cell disease diagnosis were excluded. Results: Data from 4059 children were reviewed; 51% were female; 62% Black, 13% Latino, 7% White; 83% had public or no insurance. 48% had ZPP ≥35 mcg/dL. There was no association of abnormal ZPP with gender, Black/White race, or insurance type. Discussion: Nearly half the children in this study had an abnormal ZPP, a rate not statistically different from that reported by Lozoff et al in Detroit (Am J Hematol 2007;82:112), suggesting that the prevalence of ID in urban low-income children may be much higher than the 9.2% reported by NHANES. NHANES' ID definition, which requires that 2 of 3 iron status indicators be abnormal, may be too restrictive, given that some indicators (ZPP and ferritin) are highly specific for ID. Furthermore, given its low cost and high specificity, ZPP should be considered as a screening test for ID.