RESUMEN
INTRODUCTION AND OBJECTIVE: The World Food Programme and the Office of the United Nations High Commissioner for Refugees organized a meeting of experts to discuss evaluation of micronutrient interventions under special circumstances, such as emergency and refugee situations. RESULTS: Multimicronutrient interventions for groups with higher needs may include home fortification products for young children or supplements for pregnant and lactating women. The choice of preparation should be guided by target group needs, evidence of efficacy of a product or its compounds, acceptability, and cost-effectiveness. Different designs can be used to assess whether an intervention has the desired impact. First, program implementation and adherence must be ascertained. Then, impact on micronutrient status can be assessed, but design options are often limited by logistic challenges, available budget, security issues, and ethical and practical issues regarding nonintervention or placebo groups. Under these conditions, a plausibility design using pre- and postintervention cross-sectional surveys, a prospective cohort study, or a step-wedge design, which enrolls groups as they start receiving the intervention, should be considered. Post hoc comparison of groups with different adherence levels may also be useful. Hemoglobin is often selected as an impact indicator because it is easily measured and tends to respond to change in micronutrient status, especially iron. However, it is not a very specific indicator of micronutrient status, because it is also influenced by inflammation, parasitic infestation, physiological status (age, pregnancy), altitude, and disorders such as thalassemia and sickle cell disease. CONCLUSION: Given the constraints described above, replicability of impact in different contexts is key to the validation of micronutrient interventions.
Asunto(s)
Anemia Ferropénica/epidemiología , Servicios de Alimentación/organización & administración , Promoción de la Salud/organización & administración , Oligoelementos/administración & dosificación , Oligoelementos/deficiencia , Adolescente , Anemia Ferropénica/prevención & control , Niño , Preescolar , Suplementos Dietéticos , Femenino , Alimentos Fortificados , Hemoglobinas/análisis , Humanos , Lactante , Hierro de la Dieta/administración & dosificación , Lactancia/efectos de los fármacos , Masculino , Necesidades Nutricionales , Estado Nutricional , Cooperación del Paciente , Embarazo , PrevalenciaRESUMEN
BACKGROUND: The need for prophylactic iron during pregnancy is uncertain. OBJECTIVE: We tested the hypothesis that administration of a daily iron supplement from enrollment to 28 wk of gestation to initially iron-replete, nonanemic pregnant women would reduce the prevalence of anemia at 28 wk and increase birth weight. DESIGN: Between June 1995 and September 1998, 513 low-income pregnant women in Cleveland were enrolled in the study before 20 wk of gestation. Of these, 275 had a hemoglobin concentration >/= 110 g/L and a ferritin concentration >/= 20 micro g/L and were randomly assigned to receive a monthly supply of capsules containing either 30 mg Fe as ferrous sulfate or placebo until 28 wk of gestation. At 28 and 38 wk of gestation, women with a ferritin concentration of 12 to < 20 micro g/L or < 12 micro g/L received 30 and 60 mg Fe/d, respectively, regardless of initial assignment. Almost all the women received some supplemental iron during pregnancy. We obtained infant birth weight and gestational age at delivery for 117 and 96 of the 146 and 129 women randomly assigned to receive iron and placebo, respectively. RESULTS: Compared with placebo, iron supplementation from enrollment to 28 wk of gestation did not significantly affect the overall prevalence of anemia or the incidence of preterm births but led to a significantly higher mean (+/- SD) birth weight (206 +/- 565 g; P = 0.010), a significantly lower incidence of low-birth-weight infants (4% compared with 17%; P = 0.003), and a significantly lower incidence of preterm low-birth-weight infants (3% compared with 10%; P = 0.017). CONCLUSION: Prenatal prophylactic iron supplementation deserves further examination as a measure to improve birth weight and potentially reduce health care costs.
Asunto(s)
Anemia Ferropénica/prevención & control , Peso al Nacer/efectos de los fármacos , Compuestos Ferrosos/farmacología , Resultado del Embarazo , Adulto , Femenino , Ferritinas/sangre , Compuestos Ferrosos/administración & dosificación , Humanos , Recién Nacido , EmbarazoRESUMEN
This paper provides a synopsis of the experience in combating iron deficiency in industrialized countries and identifies the reasons for the considerable success and future challenges. Significant progress has been made over the last century in reducing and even eliminating iron deficiency in many industrialized countries. Current estimates are that the prevalence of iron deficiency has declined to <20% in many of these countries, even among women and young children, compared with 30 to 70% in many developing countries. The reasons for this success cannot be attributed solely to a single approach but rather to a range of factors that have occurred over time as a result of both economic development and the implementation of specific policies. Several factors have contributed to improving both iron intakes and reducing iron losses; these include fortification, supplementation, dietary diversification and public health measures. For example, the decline in anemia in infants can be attributed to the introduction of iron-fortified formula and complementary foods in the 1960s to 1970s. Similarly, the enrichment and fortification of cereals with iron that began during World War II in North America and Europe is a result of effective public-private partnerships. Despite these successes, iron deficiency remains a public health concern in industrialized countries for selected subgroups such as women of reproductive age with excess menstrual losses and pregnant women who cannot meet increased requirements from the diet alone. Constant vigilance and innovative approaches for screening and combating this problem are thus still required even in developed countries.
Asunto(s)
Anemia Ferropénica , Países Desarrollados , Hierro de la Dieta/uso terapéutico , Adulto , Anemia Ferropénica/tratamiento farmacológico , Anemia Ferropénica/epidemiología , Anemia Ferropénica/prevención & control , Niño , Femenino , Humanos , Necesidades Nutricionales , PrevalenciaRESUMEN
Compared with the industrialized nations, the challenges of combating iron (Fe) deficiency in developing countries include the far greater magnitude of the problem, the more limited resources and the more complex nature of the setting. The two groups most affected by Fe deficiency are young children and women of reproductive age. Infant diets in developing countries are low in iron, due to less use of industry prepared foods and much lower consumption of food from animal sources. Successful experiences in countries such as Chile and the United States have shown that it is feasible to reduce anemia levels in young children through the use of fortified infant food products and low cost weaning foods. In settings in which people are already using processed foods, the cost of improving the nutritional value of these foods is marginal compared with the significant benefits. However, costs and accessibility by the poorest are important concerns, and other options such as supplementation and efforts to improve complementary feeding also require attention. The high prevalence of iron and other micronutrient deficiencies due to poor diets and/or infections among women before and during pregnancy calls for strategies such as fortification and periodic supplementation. Experience to date suggests that fortification of staples (e.g., wheat flour) is a cost-effective and feasible strategy, but regulatory monitoring is required to demonstrate effectiveness and ensure quality. Supplementation is still required for all pregnant women, however, and challenges remain in finding ways to improve coverage and compliance. In summary, effectively combining and balancing the needs of program implementation, research and community involvement will help combat Fe deficiency.
Asunto(s)
Anemia Ferropénica/prevención & control , Países en Desarrollo , Hemoglobinas , Hierro de la Dieta/administración & dosificación , Anemia Ferropénica/epidemiología , Niño , Femenino , Alimentos Fortificados/economía , Humanos , Lactante , Masculino , Necesidades Nutricionales , Embarazo , PrevalenciaRESUMEN
Iron supplementation is a commonly used strategy to meet the increased requirements of at-risk groups, such as women of childbearing age, especially during pregnancy. Other at-risk groups for which iron supplementation may be appropriate include infants, young children, adolescents and the elderly. There is a need to consider iron supplementation as part of a comprehensive strategy for the prevention of iron deficiency, and not just as a treatment for anemia that is stopped as soon as clinical improvement is noted. Experience in developing countries indicates that often the poorest women with the most deficient intakes are the least likely to receive iron supplements during pregnancy. Providing supplements to women during antenatal care visits is useful but often inadequate, so other delivery channels must also be explored, including private sector markets and community networks. Communication efforts must be expanded to increase understanding of the importance of taking supplements and to address any fears or misconceptions relating to supplementation. Overall, we must increase the capacity of individuals and communities to define, analyze and act to address their own health needs.