RESUMEN
Large-scale food fortification (LSFF) has been recognized as one of the most cost-effective interventions to improve the intake of vitamins and minerals and decrease the burden of micronutrient deficiency. Indeed, the simple addition of micronutrients to staple foods, such as wheat, maize and rice, or condiments, including salt and bouillon, has tremendous potential to impact malnutrition. However, most LSFF programs have been poorly designed and have not taken into consideration critical inputs, including current levels of nutrient inadequacy and per capita consumption of different food vehicles when deciding which nutrients to add and at what concentrations. LSFF programs, like some other nutrition interventions, also tend to have low coverage and reach and lack monitoring to measure this and course correct. These program design flaws have resulted in limited effectiveness and have made it difficult to determine how best to harmonize LSFF with other interventions to reduce micronutrient deficiencies, including efforts to enhance dietary diversity, biofortification and supplementation. Furthermore, LSFF has often been touted as a population-based intervention, but in fact has heterogenous effects among sub-groups, particularly those with limited access to or inability to afford fortified foods, as well as those with higher physiological requirements, such as pregnant and lactating women. This article focuses on these limitations and the concerted efforts underway to improve the collection, analysis, and use of data to better plan LSFF programs, track implementation, and monitor coverage and impact. This includes a more sophisticated secondary analysis of existing data, innovations to increase the frequency of primary data collection and programmatically relevant visualizations of data of sub-national estimates. These improvements will enable better use of data to target resources and programmatic efforts to reach those who stand to benefit most from fortification.
Asunto(s)
Alimentos Fortificados , Desnutrición , Embarazo , Femenino , Humanos , Lactancia , Desnutrición/epidemiología , Desnutrición/prevención & control , Micronutrientes , Fuerza de la ManoRESUMEN
Adequate calcium intake is essential for health, especially for infants, children, adolescents, and women, yet is difficult to achieve with local foods in many low- and middle-income countries. Previous analysis found it was not always possible to identify food-based recommendations (FBRs) that reached the calcium population recommended intake (PRI) for these groups in Bangladesh, Guatemala, and Uganda. We have modeled the potential contribution of calcium-fortified drinking water or wheat flour to FBR sets, to fill the remaining intake gaps. Optimized diets containing fortified products, with calcium-rich local foods, achieved the calcium PRI for all target groups. Combining fortified water or flour with FBRs met dietary intake targets for adolescent girls in all geographies and allowed a reduction from 3-4 to the more feasible 1-2 FBRs. Water with a calcium concentration of 100 mg/L with FBRs was sufficient to meet calcium targets in Uganda, but higher concentrations (400-500 mg/L) were mostly required in Guatemala and Bangladesh. Combining calcium-fortified wheat flour at 400 mg/100 g of flour and the FBR for small fish resulted in diets meeting the calcium PRI in Bangladesh. Calcium-fortified water or flour could improve calcium intake for vulnerable populations, especially when combined with FBRs based on locally available foods.
Asunto(s)
Calcio de la Dieta , Harina , Alimentos Fortificados , Bangladesh , Calcio , Dieta , Guatemala , Triticum , Uganda , Agua , Humanos , Femenino , Adolescente , Adulto , Preescolar , NiñoRESUMEN
Thiamine (vitamin B1) is an essential micronutrient required as a cofactor in many metabolic processes. Clinical symptoms of thiamine deficiency are poorly defined, hence biomarkers of thiamine status are important. The erythrocyte transketolase activity coefficient (ETKac) is a sensitive measure of thiamine status, but its interpretation may be confounded where the availability of the transketolase enzyme is limited. Basal ETK activity per gram of hemoglobin provides a complementary biomarker of thiamine status; however, its measurement and calculation are poorly described. Here, we describe in detail the assessment of basal ETK activity, including the calculation of path length in microplates and the molar absorption coefficient of NADH specific to the assay, and the measurement of hemoglobin in sample hemolysates. To illustrate the application of the methods, we present ETKac and basal ETK activity from women in The Gambia and UK. In conclusion, we present a clear protocol for the measurement of basal ETK activity that will permit the harmonization of methods to improve replication between laboratories.
Asunto(s)
Deficiencia de Tiamina , Tiamina , Humanos , Femenino , Transcetolasa , Eritrocitos/metabolismo , Deficiencia de Tiamina/diagnóstico , Hemoglobinas , BiomarcadoresRESUMEN
Inadequate dietary calcium intake is a global public health problem that disproportionately affects low- and middle-income countries. However, the calcium status of a population is challenging to measure, and there are no standard methods to identify high-risk communities even in settings with an elevated prevalence of a disease caused or exacerbated by low calcium intake (e.g., rickets). The calcium status of a population depends on numerous factors, including intake of calcium-rich foods; the bioavailability of the types of calcium consumed in foods and supplements; and population characteristics, including age, sex, vitamin D status, and genetic attributes that influence calcium retention and absorption. The aim of this narrative review was to assess candidate indicators of population-level calcium status based on a range of biomarkers and measurement methods, including dietary assessment, calcium balance studies, hormonal factors related to calcium, and health outcomes associated with low calcium status. Several promising approaches were identified, but there was insufficient evidence of the suitability of any single indicator to assess population calcium status. Further research is required to develop and validate specific indicators of calcium status that could be derived from the analysis of data or samples that are feasibly collected in population-based surveys.
Asunto(s)
Raquitismo , Deficiencia de Vitamina D , Humanos , Calcio de la Dieta , Calcio , Vitamina DRESUMEN
OBJECTIVE: Antenatal multiple micronutrient supplements (MMS) are a cost-effective intervention to reduce adverse pregnancy and birth outcomes. However, the current WHO recommendation on the use of antenatal MMS is conditional, partly due to concerns about the effect on neonatal mortality in a subgroup of studies comparing MMS with iron and folic acid supplements (IFA) containing 60 mg of iron. We aimed to assess the effect of MMS vs IFA on neonatal mortality stratified by iron dose in each supplement. METHODS: We updated the neonatal mortality analysis of the 2020 WHO guidelines using the generic inverse variance method and applied the random effects model to calculate the effect estimates of MMS vs. IFA on neonatal mortality in subgroups of trials (n=13) providing the same or different amounts of iron, i.e. MMS with 60 mg of iron vs IFA with 60 mg of iron; MMS with 30 mg of iron vs IFA with 30 mg of iron; MMS with 30 mg of iron vs IFA with 60 mg of iron; and MMS with 20 mg of iron vs IFA with 60 mg of iron. RESULTS: There were no statistically significant differences in neonatal mortality between MMS and IFA within any of the subgroups of trials. Analysis of MMS with 30 mg vs IFA with 60 mg of iron (7 trials, 14,114 participants), yielded a nonsignificant Risk Ratio (RR) of 1.12 (95% CI 0.83 to 1.50). CONCLUSION: Neonatal mortality did not differ between MMS and IFA regardless of iron dose in either supplement.
RESUMEN
Antenatal multiple micronutrient supplements (MMS) are more effective than iron and folic acid (IFA) supplements in reducing adverse pregnancy outcomes. Questions remain, however, about the ability of MMS to prevent anemia as effectively as IFA, especially at a lower dose of daily iron and in areas of high anemia prevalence. Analyzing data from 11 trials from a recent Cochrane review, we compared MMS to IFA, delivering either 30 or 60 mg of iron, in sustaining hemoglobin and preventing third trimester anemia and iron deficiency anemia (IDA), accounting for daily iron dose, total supplemental iron intake, and baseline prevalence of anemia. There were no differences between MMS and IFA in third trimester hemoglobin concentration or risks of anemia or IDA by iron dose or total supplemental iron consumed. MMS providing 30 mg of iron was comparable to IFA with 60 mg of iron: mean hemoglobin difference of -0.26 g/L (95% CI: -1.41 to 0.89), risk ratios of 0.99 (95% CI: 0.92-1.07) for anemia, and 1.31 (95% CI: 0.66-2.60) for IDA. Baseline prevalence of anemia did not explain heterogeneity in findings. Compared to IFA, MMS results in comparable hemoglobin concentration and protection against anemia during pregnancy, independently of iron dose.
Asunto(s)
Anemia Ferropénica , Anemia , Anemia/epidemiología , Anemia Ferropénica/tratamiento farmacológico , Anemia Ferropénica/epidemiología , Anemia Ferropénica/prevención & control , Suplementos Dietéticos , Femenino , Ácido Fólico/uso terapéutico , Hemoglobinas , Humanos , Hierro/uso terapéutico , Micronutrientes , EmbarazoRESUMEN
Calcium intake remains inadequate in many low- and middle-income countries, especially in Africa and South Asia, where average intakes can be below 400 mg/day. Given the vital role of calcium in bone health, metabolism, and cell signaling, countries with low calcium intake may want to consider food-based approaches to improve calcium consumption and bioavailability within their population. This is especially true for those with low calcium intake who would benefit the most, including pregnant women (by reducing the risk of preeclampsia) and children (by reducing calcium-deficiency rickets). Specifically, some animal-source foods that are naturally high in bioavailable calcium and plant foods that can contribute to calcium intake could be promoted either through policies or educational materials. Some food processing techniques can improve the calcium content in food or increase calcium bioavailability. Staple-food fortification with calcium can also be a cost-effective method to increase intake with minimal behavior change required. Lastly, biofortification is currently being investigated to improve calcium content, either through genetic screening and breeding of high-calcium varieties or through the application of calcium-rich fertilizers. These mechanisms can be used alone or in combination based on the local context to improve calcium intake within a population.
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Calcio , Alimentos Fortificados , Animales , Disponibilidad Biológica , Huesos , Calcio de la Dieta , Femenino , Humanos , EmbarazoRESUMEN
Most low- and middle-income countries present suboptimal intakes of calcium during pregnancy and high rates of mortality due to maternal hypertensive disorders. Calcium supplementation during pregnancy is known to reduce the risk of these disorders and associated complications, including preeclampsia, maternal morbidity, and preterm birth, and is, therefore, a recommended intervention for pregnant women in populations with low dietary calcium intake (e.g., where ≥25% of individuals in the population have intakes less than 800 mg calcium/day). However, this intervention is not widely implemented in part due to cost and logistical issues related to the large dose and burdensome dosing schedule (three to four 500-mg doses/day). WHO recommends 1.5-2 g/day but limited evidence suggests that less than 1 g/day may be sufficient and ongoing trials with low-dose calcium supplementation (500 mg/day) may point a path toward simplifying supplementation regimens. Calcium carbonate is likely to be the most cost-effective choice, and it is not necessary to counsel women to take calcium supplements separately from iron-containing supplements. In populations at highest risk for preeclampsia, a combination of calcium supplementation and food-based approaches, such as food fortification with calcium, may be required to improve calcium intakes before pregnancy and in early gestation.
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Hipertensión Inducida en el Embarazo , Preeclampsia , Nacimiento Prematuro , Calcio/uso terapéutico , Calcio de la Dieta/uso terapéutico , Suplementos Dietéticos , Femenino , Humanos , Hipertensión Inducida en el Embarazo/prevención & control , Recién Nacido , Preeclampsia/prevención & control , EmbarazoRESUMEN
Prenatal micronutrient supplements are cost-effective in reducing nutritional deficiencies and adverse pregnancy and birth outcomes. However, poor adherence remains a potential barrier to the successful implementation of these supplementation programs. This systematic review assessed the effectiveness of interventions designed to increase adherence to prenatal micronutrient supplementation. Following the Cochrane Collaboration Methodology, literature searches were conducted in six electronic databases and gray literature (on July 24, 2020), and abstract screening, data extraction, and risk of bias assessment were conducted independently by two reviewers. We included 22 studies. Interventions that resulted in increased adherence were most of the education-based strategies, consumption monitoring by volunteer health workers or family members, SMS reminders, free provision of supplements, a multicomponent intervention with community mobilization, and a participatory action research intervention. In several studies, increased adherence was accompanied by beneficial effects on pregnancy and birth outcomes. Given the heterogeneity of study designs and methods used to define and measure adherence, a meta-analysis was not appropriate. We identified several potentially effective strategies to improve supplementation adherence, which may need to be adapted to specific contexts when considered for program implementation. However, additional high-quality studies are critically needed to effectively guide policies and programs.
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Suplementos Dietéticos , Micronutrientes/administración & dosificación , Cooperación del Paciente , Femenino , Humanos , Evaluación de Resultado en la Atención de Salud , Cooperación del Paciente/psicología , Cooperación del Paciente/estadística & datos numéricos , Embarazo , Atención Prenatal/métodos , Educación Prenatal/métodos , Fenómenos Fisiologicos de la Nutrición PrenatalRESUMEN
Micronutrient supplementation during pregnancy has been shown to be a cost-effective method to reduce the risk of adverse pregnancy and birth outcomes. However, one of the main barriers to the successful implementation of a micronutrient supplementation program in pregnancy is poor adherence. Our review will assess the effectiveness of interventions designed to increase adherence to micronutrient supplements in pregnancy. Following the Cochrane Collaboration Methodology, we will start by conducting the literature searches on Medline (via PubMed), Embase, Scopus, Web of Science, and Cochrane Library, in addition to sources of gray literature, to retrieve all the available relevant studies. We will include randomized controlled trials and nonrandomized studies with a control group, where participants are pregnant women taking any micronutrient supplements in the context of antenatal care globally. We will include studies with targeted interventions designed to improve adherence to micronutrient supplementation in pregnant women compared with (1) usual care or no intervention or (2) other targeted micronutrient adherence intervention. Abstract selection, data extraction, and risk of bias assessment (according to the type of studies) will be conducted by two independent reviewers. The pooled results will be reported using the standardized mean differences for continuous data, and odds ratio or risk ratio for dichotomous data. We will assess sources of heterogeneity and publication bias. By following this protocol, we will systematically assess and synthesize the existing evidence about interventions designed to increase adherence to micronutrient supplementation in pregnant women. Understanding which strategies are more effective to increase the consumption of micronutrient supplements during this critical stage of life will have significant implications for clinicians and policymakers involved in the delivery of prenatal micronutrient supplementation interventions.
Asunto(s)
Suplementos Dietéticos , Micronutrientes , Cooperación del Paciente , Literatura de Revisión como Asunto , Femenino , Humanos , EmbarazoRESUMEN
Prenatal micronutrient deficiencies are associated with negative maternal and birth outcomes. Multiple micronutrient supplementation (MMS) during pregnancy is a cost-effective intervention to reduce these adverse outcomes. However, important knowledge gaps remain in the implementation of MMS interventions. The Child Health and Nutrition Research Initiative (CHNRI) methodology was applied to inform the direction of research and investments needed to support the implementation of MMS interventions for pregnant women in low- and middle-income countries (LMIC). Following CHNRI methodology guidelines, a group of international experts in nutrition and maternal health provided and ranked the research questions that most urgently need to be resolved for prenatal MMS interventions to be successfully implemented. Seventy-three research questions were received, analyzed, and reorganized, resulting in 35 consolidated research questions. These were scored against four criteria, yielding a priority ranking where the top 10 research options focused on strategies to increase antenatal care attendance and MMS adherence, methods needed to identify populations more likely to benefit from MMS interventions and some discovery issues (e.g., potential benefit of extending MMS through lactation). This exercise prioritized 35 discrete research questions that merit serious consideration for the potential of MMS during pregnancy to be optimized in LMIC.
Asunto(s)
Suplementos Dietéticos , Micronutrientes/uso terapéutico , Atención Prenatal , Análisis Costo-Beneficio , Femenino , Humanos , Política Nutricional/tendencias , Ciencias de la Nutrición/tendencias , Pobreza , EmbarazoRESUMEN
Inadequate micronutrient intakes are relatively common in low- and middle-income countries (LMICs), especially among pregnant women, who have increased micronutrient requirements. This can lead to an increase in adverse pregnancy and birth outcomes. This review presents the conclusions of a task force that set out to assess the prevalence of inadequate micronutrient intakes and adverse birth outcomes in LMICs; the data from trials comparing multiple micronutrient supplements (MMS) that contain iron and folic acid (IFA) with IFA supplements alone; the risks of reaching the upper intake levels with MMS; and the cost-effectiveness of MMS compared with IFA. Recent meta-analyses demonstrate that MMS can reduce the risks of preterm birth, low birth weight, and small for gestational age in comparison with IFA alone. An individual-participant data meta-analysis also revealed even greater benefits for anemic and underweight women and female infants. Importantly, there was no increased risk of harm for the pregnant women or their infants with MMS. These data suggest that countries with inadequate micronutrient intakes should consider supplementing pregnant women with MMS as a cost-effective method to reduce the risk of adverse birth outcomes.
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Suplementos Dietéticos , Micronutrientes/administración & dosificación , Países en Desarrollo , Femenino , Humanos , Recién Nacido , Micronutrientes/deficiencia , Embarazo , Resultado del EmbarazoRESUMEN
BACKGROUND: Thiamin deficiency is a major public health concern in several low- and middle-income countries (LMICs)-current attention to the problem is lacking. AIM: This review discusses prevalence of thiamin insufficiency and thiamin-deficiency disorders (TDDs) in LMICs, outlines programmatic experience with thiamin interventions, and offers recommendations to improve public-health and research attention to thiamin in LMICs. DISCUSSION: Thiamin insufficiency, i.e. low-blood-thiamin status, is endemic among several Southeast Asian countries: Cambodia (70-100% of infants and 27-100% of reproductive-age women); Laos (13% of hospitalized infants); Thailand (16-25% of children and 30% of elderly adults). Thiamin deficiency accounts for up to 45% of under-5 deaths in Cambodia, 34% of infant deaths in Laos, and 17% of infant deaths in Myanmar. Deficiency also exists in Africa, Asia, and the Americas, but these instances have typically been isolated. Exclusively breastfed infants of thiamin-deficient mothers are at highest risk for TDD and related death. Intervention strategies that have been employed to combat thiamin deficiency include food processing, fortification, supplementation, dietary diversification, and dietary behaviors, all of which have shown varying levels of effectiveness. CONCLUSIONS: We recommend universal thiamin-fortification of context-specific staple-foods in LMICs as a promising solution, as well as thiamin supplementation, particularly for pregnant and lactating women. Food processing regulations, dietary diversification, and modification of dietary behaviors to increase consumption of thiamin-rich foods may provide benefits in some circumstances, especially in countries without universal fortification programs or in populations dependent on food aid.
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Enfermedades Endémicas , Alimentos Fortificados , Deficiencia de Tiamina/tratamiento farmacológico , Deficiencia de Tiamina/epidemiología , Tiamina/uso terapéutico , Complejo Vitamínico B/uso terapéutico , Asia Sudoriental/epidemiología , Cambodia/epidemiología , Países en Desarrollo , Femenino , Humanos , Laos/epidemiología , Micronutrientes , Mianmar/epidemiología , Estado Nutricional , Embarazo , Fenómenos Fisiologicos de la Nutrición Prenatal , Prevalencia , Factores de Riesgo , Tailandia/epidemiologíaRESUMEN
Vitamin D is an essential nutrient for bone health and may influence the risks of respiratory illness, adverse pregnancy outcomes, and chronic diseases of adulthood. Because many countries have a relatively low supply of foods rich in vitamin D and inadequate exposure to natural ultraviolet B (UVB) radiation from sunlight, an important proportion of the global population is at risk of vitamin D deficiency. There is general agreement that the minimum serum/plasma 25-hydroxyvitamin D concentration (25(OH)D) that protects against vitamin D deficiency-related bone disease is approximately 30 nmol/L; therefore, this threshold is suitable to define vitamin D deficiency in population surveys. However, efforts to assess the vitamin D status of populations in low- and middle-income countries have been hampered by limited availability of population-representative 25(OH)D data, particularly among population subgroups most vulnerable to the skeletal and potential extraskeletal consequences of low vitamin D status, namely exclusively breastfed infants, children, adolescents, pregnant and lactating women, and the elderly. In the absence of 25(OH)D data, identification of communities that would benefit from public health interventions to improve vitamin D status may require proxy indicators of the population risk of vitamin D deficiency, such as the prevalence of rickets or metrics of usual UVB exposure. If a high prevalence of vitamin D deficiency is identified (>20% prevalence of 25(OH)D < 30 nmol/L) or the risk for vitamin D deficiency is determined to be high based on proxy indicators (e.g., prevalence of rickets >1%), food fortification and/or targeted vitamin D supplementation policies can be implemented to reduce the burden of vitamin D deficiency-related conditions in vulnerable populations.
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Salud Global , Luz Solar , Deficiencia de Vitamina D/epidemiología , Suplementos Dietéticos , Alimentos Fortificados , Humanos , Encuestas Nutricionales , Estado Nutricional , PrevalenciaRESUMEN
Thiamine is an essential micronutrient that plays a key role in energy metabolism. Many populations worldwide may be at risk of clinical or subclinical thiamine deficiencies, due to famine, reliance on staple crops with low thiamine content, or food preparation practices, such as milling grains and washing milled rice. Clinical manifestations of thiamine deficiency are variable; this, along with the lack of a readily accessible and widely agreed upon biomarker of thiamine status, complicates efforts to diagnose thiamine deficiency and assess its global prevalence. Strategies to identify regions at risk of thiamine deficiency through proxy measures, such as analysis of food balance sheet data and month-specific infant mortality rates, may be valuable for understanding the scope of thiamine deficiency. Urgent public health responses are warranted in high-risk regions, considering the contribution of thiamine deficiency to infant mortality and research suggesting that even subclinical thiamine deficiency in childhood may have lifelong neurodevelopmental consequences. Food fortification and maternal and/or infant thiamine supplementation have proven effective in raising thiamine status and reducing the incidence of infantile beriberi in regions where thiamine deficiency is prevalent, but trial data are limited. Efforts to determine culturally and environmentally appropriate food vehicles for thiamine fortification are ongoing.
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Suplementos Dietéticos , Alimentos Fortificados , Salud Pública , Deficiencia de Tiamina/epidemiología , Salud Global , Humanos , Prevalencia , Factores de Riesgo , Deficiencia de Tiamina/diagnóstico , Deficiencia de Tiamina/terapiaRESUMEN
There is considerable evidence to support dietary recommendations for prevention of cancer as well as for patients undergoing or recovering from cancer treatment. We consider here implications from human, animal and in-vitro studies of the effects of dietary factors (macronutrients and micronutrients-phytochemicals) on cancer. An important epidemiology study, the China Project found a significant correlation between disease incidence and markers of animal product consumption. Evidence of the role of animal protein in the promotion of cancer also comes from animal studies. Food restriction has been shown in human and animal studies to slow cancer progression. Phytochemicals from whole plant foods are protective against oxidative stress, inhibit cell proliferation, induce cell-cycle arrest, and apoptosis, act as antiangiogenesis factors, and inhibit cyclooxygenase-2, which has been related to metastasis. Some mechanisms that mediate the effect of diet on cancer involve cell signaling through insulin factors and mammalian target of rapamycin, a nutrient sensing complex related to growth, altered gene expression through epigenetics, and the effects of microbial metabolites produced by the gut microbiota that is strongly influenced by dietary factors. The evidence accumulating for many years indicates that diet, what we eat every day, can affect disease. Besides preventing the development of cancer, this could also be harnessed to positively influence treatment outcomes as well as prevent recurrence. As research strategies developed for drug studies are not appropriate, it is important that new methodologies be developed to study these effects.