Iron supplementation in early childhood: Health benefits and risks

Department of International Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA.
American Journal of Clinical Nutrition (Impact Factor: 6.77). 01/2007; 84(6):1261-76.
Source: PubMed


The prevalence of iron deficiency among infants and young children living in developing countries is high. Because of its chemical properties--namely, its oxidative potential--iron functions in several biological systems that are crucial to human health. Iron, which is not easily eliminated from the body, can also cause harm through oxidative stress, interference with the absorption or metabolism of other nutrients, and suppression of critical enzymatic activities. We reviewed 26 randomized controlled trials of preventive, oral iron supplementation in young children (aged 0-59 mo) living in developing countries to ascertain the associated health benefits and risks. The outcomes investigated were anemia, development, growth, morbidity, and mortality. Initial hemoglobin concentrations and iron status were considered as effect modifiers, although few studies included such subgroup analyses. Among iron-deficient or anemic children, hemoglobin concentrations were improved with iron supplementation. Reductions in cognitive and motor development deficits were observed in iron-deficient or anemic children, particularly with longer-duration, lower-dose regimens. With iron supplementation, weight gains were adversely affected in iron-replete children; the effects on height were inconclusive. Most studies found no effect on morbidity, although few had sample sizes or study designs that were adequate for drawing conclusions. In a malaria-endemic population of Zanzibar, significant increases in serious adverse events were associated with iron supplementation, whereas, in Nepal, no effects on mortality in young children were found. More research is needed in populations affected by HIV and tuberculosis. Iron supplementation in preventive programs may need to be targeted through identification of iron-deficient children.

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Available from: Lora Iannotti
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    • "Negative effects of iron supplementation with normal recommended dose of iron (10 g iron salt per day) have, however, been reported in areas where malaria transmission is intense and infectious diseases are highly prevalent (Sazawal et al., 2006). Excessive iron absorption may be harmful by causing oxidative stress (that causes oxidative damage of DNA, proteins, lipids and other tissue injuries), interference with absorption or metabolism of other nutrients and suppression of other critical enzymatic activities (Iannotti et al., 2006). Recently, there has been growing concern about the effect of iron supplementation on increased susceptibility to infections for children living in malaria hyperendemic areas. "
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    ABSTRACT: Iron deficiency anaemia is a public health problem in Tanzania especially among children under the age of five years. In malaria holoendemic areas, control of anaemia by supplementation with iron has been reported to increase serious adverse events. The World Health Organization recommends that, programs to control anaemia in such areas should go concurrently with malaria control programmes. The objectives of the study were to: (i) to determine if a supplement providing 2.5 mg of iron as ferric EDTA and 2.5 mg of iron as ferrous lactate (low dose) is as effective in correcting anaemia as a supplement providing the standard 10 mg of iron as ferrous lactate (high dose); and ii) determine if iron supplementation increased the risk of malaria. This study was carried out in Mvomero District of east-central Tanzania. Two groups (69 and 70 subjects per treatment) of moderately anaemic children (7.0–9.1 g of Hb/dl), received one of the two micronutrient supplements differing only in iron content for a period of 60 days. Results showed that, the average haemoglobin (Hb) concentration improved from 8.30±0.60 g/dl to 11.08±1.25 g/dl. The average weight-for-age for all children increased from 16.0 to 20.6% while their weight-for-height increased from 4.0 to 13.3%. The incidence of asymptomatic and symptomatic malaria ranged from 10.0 to 10.4% at all time points with no apparent increase in malaria severity due to iron supplementation. Overall, there was a significant reduction in anaemia during the 60 day supplementation period. This study demonstrated that, micronutrient supplements containing low-dose ferric-EDTA is just as effective as the high dose iron in reducing anaemia and can be safely utilized in malaria holoendemic areas to control iron deficiency anaemia. It is recommended that, a large study should be conducted to affirm the effectiveness of the low-dose ferric-EDTA in controlling iron deficiency anaemia among underfive children.
    Full-text · Article · May 2014 · Tanzania journal of health research
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    • "Studies have shown that iron deficiency causes delay in cognitive development and poor motor and sensory system functioning and that iron supplementation in early years may prevent these complications among children [4]. Conversely, there is an evidence suggesting that routine iron treatment in non-iron deficient children may have adverse consequences for morbidity and infections [5,6]. Therefore, it is very important to detect iron deficiency (ID) at its earliest stage in children especially in a low resource setting and replenish the iron stores by proper supplementation, thereby preventing many of the adverse developmental and behavioral effects caused by IDA. "
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    ABSTRACT: Current strategy to identify iron deficiency anemia relies on markers involving high costs. Reports have suggested red cell distribution width (RDW) as a potential screening test for identifying iron deficiency anemia (IDA) but studies in pediatric populations are lacking. Our study elucidates the discriminative ability of RDW for detecting IDA among young children. 2091 blood reports of children aged 1-3 years from an urban low socio-economic population of Delhi were analyzed to evaluate the sensitivity of RDW in discriminating IDA using receiver's operating characteristic curve. Hemoglobin and RDW were estimated using coulter, zinc protoporphyrin with AVIV fluorometer and serum ferritin by enzyme linked immunosorbent assay. A total of 1026 samples were classified as iron deficient anemia using gold standard. As a marker of overall efficiency, area under the curve for RDW was 0.83 (95% CI, 0.81- 0.84; p < 0.001). Sensitivity of RDW at cut-off of 18% to detect iron deficiency anemia was 76.5% and specificity 73.1% yielding a positive predictive value of 73% and negative predictive value of 76%. At a cut-off of RDW 16.4%, the sensitivity was 94% and at a cut-off of 21%, the specificity was 95%. Combination of hemoglobin <=10 g/dL and RDW >15%, yielded a sensitivity of 99% and specificity of 90%. These data suggest that simple coulter analysis estimating hemoglobin and RDW can be used for identification of children in need for iron therapy. In India and similar settings, RDW >15% with hemoglobin <=10.0 g/dL identifies iron deficient anemic children without need for iron status markers which could help reduce cost of management especially in poor settings.Trial registration: NCT00255385.
    Full-text · Article · Jan 2014 · BMC Pediatrics
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    • "Specifically, iron deficiency can lead to deficits in memory and behavioural regulation as iron is required to make neurotransmitters such as dopamine, epinephrine, and serotonin while impaired myelination contributes to deficits in motor function [15–17]. Some of these impairments are thought to be irreversible if they occur at an early age and the consequences may continue even after treatment, reinforcing the importance of prevention [15, 18, 19]. "
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    ABSTRACT: The aim of this study was to investigate the characteristics of our hospitalized patients with the diagnosis of iron deficiency anemia (IDA) and effects of the IDA prevention project of the Turkish Ministry of Health which was started in 2004. The recommended dose of prophylactic iron supplementation was 1-2 mg/kg/day. The files of 1519 patients who were hospitalized to Konya Education and Research Hospital Pediatrics Clinic were reviewed. A total of 50 patients consisting of 35 boys and 15 girls with the mean age of 16,59 ± 1,68 months were included into the study. The prevalence of IDA was 3.29% (boys: 4.23%, girls: 2.1%). Hgb and Hct of the patients >24 months were significantly higher than those of the patients with the age of 6-12 months. Iron supplementation receiving rates were very low. Of the 28 patients older than 12 months, only 44% of them had received a full course of iron supplementation for 8 months. In conclusion, although prophylactic iron supplementation lowered the prevalences of IDA, receiving rates of iron supplementation were not adequate. While IDA is still a public health problem, prophylactic approaches should be carried out more effectively.
    Full-text · Article · Dec 2013 · Anemia
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