Modeling food fortification contributions to micronutrient requirements in Malawi using Household Consumption and Expenditure Surveys

Nutritional Anemia Reductions Due to Food Fortification Among Women of Childbearing Age: A Literature Review and Bayesian Meta-Analysis

Food fortification can deliver essential micronutrients to populations at a large scale, thereby reducing nutritional anemia. This study aimed to review and meta-analyze the literature on the impact of wheat flour, maize flour, rice, and oil (singly or combined) fortification on women's (10-49 years) hemoglobin and anemia. A search of 17 databases yielded 2284 results. Longitudinal, pre-post cross-sectional, efficacy, and effectiveness studies were included. Primary outcomes were changes in hemoglobin concentration and anemia prevalence. Studies were synthesized using arm-based network meta-analysis. In women who consumed fortified rice, hemoglobin mean change was 3.24 g/L (95% credibility interval (CrI) 0.9, 5.98), higher than for women in the control, with a 99.1% probability that the true mean difference was > 0. Hemoglobin was 2.08 g/L (95% CrI -0.76, 4.35) higher in women who consumed wheat flour versus control, with a 93.5% probability that the true mean difference was > 0. After rice fortification, anemia prevalence in women was 1.38 percentage points (95% CrI -106.6, 99.2) lower than for control women, with a 51.2% probability that the true mean difference was < 0. Wheat flour fortification decreased anemia prevalence by 1.84 percentage points (95% CrI -93.4, 92.4) with a 52.72% probability that the true mean difference was < 0. The treatment effects of fortified maize flour and fortified oil could not be calculated due to the absence of control arms compared to the intervention arms. Fortified rice and wheat flour appear likely to modestly increase hemoglobin and may also reduce anemia in women of childbearing age.

Informing the Design of Large-Scale Food Fortification Programs with Secondary Data: Pilot Results from Nigeria and Zambia

Background

Large-scale food fortification (LSFF) can improve micronutrient intake, but low-income and middle-income countries often lack resources to collect data for LSFF decision making. We designed a methodology using existing data and methods to inform LSFF programming.

Objectives

This study aimed to pilot a methodology using existing diet, market, and diet cost data and assess its implementation feasibility and usefulness for LSFF decision making.

Methods

We used household food consumption/availability data from Nigeria and Zambia to assess dietary micronutrient inadequacy and model contributions of LSFF. Market survey (Nigeria) and agrifood information system (Zambia) data were used to estimate availability of fortifiable foods. We used Cost of the Diet software to estimate affordability of an adequate diet in Zambia. We engaged country stakeholders to determine modeling parameters and assess methodology implementation.

Results

The analyses took ∼6 mo and cost ∼150,000 USD (Nigeria) and ∼250,000 USD (Zambia). Results showed diets were inadequate to meet vitamin A, folate, and zinc requirements of 32%-67% of households in Nigeria and 51%-83% of households in Zambia. Modeling existing LSFF in Nigeria demonstrated improved micronutrient adequacy of diets, with further improvements possible with rice fortification. In Zambia, existing vitamin A-fortified sugar marginally reduced inadequacy. Introducing mandatory wheat flour and/or maize flour fortification could reduce folate and zinc inadequacies. The market assessment demonstrated widespread availability of fortifiable edible oil, sugar, and wheat flour, but not fortifiable maize flour. The cost of the diet in Zambia with LSFF was similar to the cost without LSFF. Stakeholders found the methodology's components together generated useful, timely evidence for LSFF programming.

Conclusions

Our methodology showed opportunities for improving the micronutrient adequacy of diets in Nigeria and Zambia through LSFF. The methodology generated evidence that stakeholders agreed can support LSFF planning. Investments and strategies are needed to strengthen capacity to conduct the assessments, reduce costs, and streamline methods.

The cost-efficiency of vitamin A supplementation services in Kenya: An assessment of a Malezi Bora event in Kenya

Vitamin A supplementation (VAS) remains a cornerstone of global child survival programs. As available funding declines, countries are seeking alternative delivery platforms. We examine a VAS-deworming delivery event in 2019 in Kenya, called Malezi Bora (MB), that employed four delivery platforms: health clinics, Early Childhood Development centers, community distribution points, and home visits. VAS coverage data were collected via household surveys in four subcounties, three of which received financial and technical assistance, and one of which received technical assistance only. Data on costs were collected using structured and semi-structured questionnaires. Only one subcounty achieved the targeted VAS coverage rate (80%) across most age subgroups; the subcounty not receiving financial assistance covered just 37% of children 6-59 months of age. Two other funded subcounties had higher coverage rates but failed to achieve 80% coverage for any age subgroup. Most children in the funded subcounties received VAS in their homes. Most children in the unfunded subcounty received VAS at a health facility. Being aware of MB was the most important factor associated with receiving VAS. Cost per child reached, including opportunity costs, varied across subcounties from $1.81 to $11.13 USD. Salaries were the main cost drivers.

Estimating food consumption, micronutrient intake and the contribution of large-scale food fortification to micronutrient adequacy in Tanzania

OBJECTIVE

To assess the potential contribution of large-scale food fortification (LSFF) towards meeting dietary micronutrient requirements in Tanzania.

DESIGN

We used household food consumption data from the National Panel Survey 2014-15 to estimate fortifiable food vehicle coverage and consumption (standardised using the adult female equivalent approach) and the prevalence at risk of inadequate apparent intake of five micronutrients included in Tanzania's fortification legislation. We modelled four LSFF scenarios: no fortification, status quo (i.e. compliance with current fortification contents) and full fortification with and without maize flour fortification.

SETTING

Tanzania.

PARTICIPANTS

A nationally representative sample of 3290 Tanzanian households.

RESULTS

The coverage of edible oils and maize and wheat flours (including products of wheat flour and oil such as bread and cakes) was high, with 91 percent, 88 percent and 53 percent of households consuming these commodities, respectively. We estimated that vitamin A-fortified oil could reduce the prevalence of inadequate apparent intake of vitamin A (retinol activity equivalent) from 92 percent without LSFF to 80 percent with LSFF at current fortification levels. Low industry LSFF compliance of flour fortification limits the contribution of other micronutrients, but a hypothetical full fortification scenario shows that LSFF of cereal flours could substantially reduce the prevalence at risk of inadequate intakes of iron, zinc, folate and vitamin B12.

CONCLUSIONS

The current Tanzania LSFF programme likely contributes to reducing vitamin A inadequacy. Policies that support increased compliance could improve the supply of multiple nutrients, but the prominence of small-scale maize mills restricts this theoretical benefit.

The Potential for Bouillon Fortification to Reduce Dietary Micronutrient Inadequacy: Modeling Analyses Using National Survey Data from Cameroon, Ghana, and Haiti

Background

Bouillon is commonly consumed in some countries where micronutrient deficiencies are prevalent, but it has not been widely adopted as a micronutrient fortification vehicle.

Objectives

We modeled the potential impacts of bouillon fortification on dietary micronutrient adequacy to inform future discussions around bouillon fortification programs.

Methods

We analyzed the dietary intake of women of reproductive age (WRA) and 1- to 5-y-old children from a national dietary survey in Cameroon, and "apparent intake" (using the nutrient density approach) of WRA, children, and men from 3 household surveys in Cameroon, Ghana, and Haiti. We examined (apparent) intake of bouillon and simulated the impacts of bouillon fortification with varying levels of vitamin A, folic acid, vitamin B12, iron, and zinc on inadequate intake (below the estimated average requirement) and intake above the tolerable upper intake level (UL). Scenarios accounted for current mandatory fortification programs and different assumptions about iron absorption from bouillon.

Results

Bouillon was consumed by >67% of households in Ghana and >90% in Haiti and Cameroon. Median (apparent) consumption ranged from 1.6 to 2.1 g/d for WRA, 0.7 to 1.0 g/d for children, and 1.8 to 2.2 g/d for men. Bouillon fortification at the highest micronutrient concentration modeled was predicted to reduce dietary inadequacy by 21-52 percentage points (pp) for vitamin A; 3-47pp for folic acid, and 4-90pp for vitamin B12, depending on the country and population group. In contrast, predicted impacts for iron were modest (2-17pp reduction) but would increase if absorption of iron from bouillon were enhanced. Simulated zinc fortification reduced inadequacy by 12-50pp, but zinc intake above the UL exceeded 10% among children in almost all scenarios.

Conclusions

Modeling indicates that bouillon fortification could improve dietary micronutrient adequacy beyond existing fortification programs. Further work is needed to identify fortification levels that meet criteria for nutritional benefit, technical and commercial feasibility, affordability, and cost-effectiveness.

Bouillon fortification as a strategy to address inequities in micronutrient adequacy of diets in Nigeria

Bouillon is a widely consumed condiment in many West African countries, including Nigeria. Although Nigeria has mandatory fortification standards for multiple food vehicles, bouillon fortification could help address remaining gaps in micronutrient intake. Using household food consumption data, we used the nutrient density method to model the additional contribution of bouillon fortified with vitamin A (40-250 µg/g bouillon), folic acid (20-120 µg/g), vitamin B12 (0.2-2 µg/g), iron (0.6-5 mg/g), and zinc (0.6-5 mg/g) for meeting micronutrient requirements of women of reproductive age (WRA) and children aged 6-59 months. Accounting for existing fortification programs, our results showed that, except for iron, the prevalence of inadequacy was substantially higher among WRA and children living in poorer and rural households. Given the ubiquity of bouillon consumption, bouillon fortification has the potential to virtually eliminate vitamin A, folate, and vitamin B12 inadequacy, reduce the prevalence of zinc inadequacy by over 20 percentage points, and improve equity in the micronutrient adequacy of diets across socioeconomic strata and urban and rural residence. Our results also suggested that designing a bouillon fortification program would require careful planning to balance reductions in inadequacy with the risk of high intakes. This evidence provides important input into decisions around bouillon fortification in Nigeria.

Food-based dietary guidelines for optimizing calcium intakes for reproductive-aged women in Ethiopia using local foods

Increasing dietary calcium intakes of Ethiopian women of reproductive age (WRA) is a public health priority for reducing pre-eclampsia in pregnancy. Using linear programming, we determined whether locally available foods consumed by WRA in nine regions (urban and rural) and two administrative cities of Ethiopia could provide 1000 mg/day of dietary calcium, and we identified food-based recommendations (FBRs) to improve dietary calcium adequacy in each region. Results showed that diets providing 1000 mg/day of calcium were feasible in eight regions (40%) of the target populations examined. It would, however, require marked changes for most populations (90%), increasing the number of servings per week of several food groups to levels close to those of high consumers in each population. The selected calcium-specific FBRs integrate well into the 2022 Ethiopian Dietary Guidelines, requiring additional messages to consume green leafy vegetables, milk, root crops, or teff (Eragrostis tef) or to consume a higher number of servings of vegetables than currently recommended, depending on the population. In conclusion, these analyses show that a food-based approach can be used to achieve dietary calcium adequacy among WRA in 40% of the populations examined. For the other populations, food-based interventions alone may be inadequate and other interventions are likely needed.

Modeled impacts of bouillon fortification with micronutrients on child mortality in Senegal, Burkina Faso, and Nigeria

Micronutrient interventions can reduce child mortality. By applying Micronutrient Intervention Modeling methods in Senegal, Burkina Faso, and Nigeria, we estimated the impacts of bouillon fortification on apparent dietary adequacy of vitamin A and zinc among children and folate among women. We then used the Lives Saved Tool to predict the impacts of bouillon fortification with ranges of vitamin A, zinc, and folic acid concentrations on lives saved among children 6-59 months of age. Fortification at 250 µg vitamin A/g and 120 µg folic acid/g was predicted to substantially reduce vitamin A- and folate-attributable deaths: 65% for vitamin A and 92% for folate (Senegal), 36% for vitamin A and 74% for folate (Burkina Faso), and >95% for both (Nigeria). Zinc fortification at 5 mg/g would avert 48% (Senegal), 31% (Burkina Faso), and 63% (Nigeria) of zinc-attributable deaths. The addition of all three nutrients at 30% of Codex nutrient reference values in 2.5 g bouillon was predicted to save an annual average of 293 child lives in Senegal (3.5% of deaths from all causes among children 6-59 months of age), 933 (2.1%) in Burkina Faso, and 18,362 (3.7%) in Nigeria. These results, along with evidence on program feasibility and costs, can help inform fortification program design discussions.

Projecting the Contribution of Provitamin A Maize Biofortification and Other Nutrition Interventions to the Nutritional Adequacy and Cost of Diets in Rural Zimbabwe

BACKGROUND

Evidence of the effectiveness of biofortified maize with higher provitamin A (PVA) to address vitamin A deficiency in rural Africa remains scant.

OBJECTIVES

This study projects the impact of adopting PVA maize for a diversity of households in an area typical of rural Zimbabwe and models the cost and composition of diets adequate in vitamin A.

METHODS

Household-level weighed food records were generated from 30 rural households during a week in April and November 2021. Weekly household intakes were calculated, as well as indicative costs of diets using data from market surveys. The impact of PVA maize adoption was modeled assuming all maize products contained observed vitamin A concentrations. The composition and cost of the least expensive indicative diets adequate in vitamin A were calculated using linear programming.

RESULTS

Very few households would reach adequate intake of vitamin A with the consumption of PVA maize. However, from a current situation of 33%, 50%-70% of households were projected to reach ≥50% of their requirements (the target of PVA), even with the modest vitamin A concentrations achieved on-farm (mean of 28.3 μg RAE per 100 g). This proportion would increase if higher concentrations recorded on-station were achieved. The estimated daily costs of current diets (mean ± standard deviation) were USD 1.43 ± 0.59 in the wet season and USD 0.96 ± 0.40 in the dry season. By comparison, optimization models suggest that diets adequate in vitamin A could be achieved at daily costs of USD 0.97 and USD 0.79 in the wet and dry seasons, respectively.

CONCLUSIONS

The adoption of PVA maize would bring a substantial improvement in vitamin A intake in rural Zimbabwe but should be combined with other interventions (e.g., diet diversification) to fully address vitamin A deficiency.

Folate and vitamin B12 status and predicted neural tube defects risk among nonpregnant women of reproductive age from the Malawi National Micronutrient Survey, 2015-2016

BACKGROUND

Maternal folate and vitamin B12 deficiency can lead to serious adverse pregnancy outcomes. There are no nationally representative estimates on folate and vitamin B12 status among women of reproductive age (WRA) in Malawi.

OBJECTIVE

We assessed folate and vitamin B12 status among nonpregnant WRA in Malawi and predicted the risk of folate-sensitive neural tube defects (NTDs) were they to become pregnant.

METHODS

Using data from the cross-sectional, nationally representative 2015-2016 Malawi Micronutrient Survey, we calculated the proportion of folate and vitamin B12 deficiency and insufficiency by demographic characteristics among 778 nonpregnant WRA (15-49 years). We predicted NTD prevalence using red blood cell (RBC) folate distributions and a published Bayesian model of the association between RBC folate and NTD risk. Analyses accounted for complex survey design.

RESULTS

Among WRA, 8.5% (95% CI: 6.2, 11.6) and 13.3% (10.0, 17.4) had serum (<7 nmol/L) and RBC folate (<305 nmol/L) deficiency, respectively. The proportion of vitamin B12 deficiency (<148 pmol/L) and insufficiency (≤221 pmol/L) was 11.8% (8.6, 16.0) and 40.6% (34.1, 47.4), respectively. RBC folate insufficiency (<748 nmol/L, defined as the concentration associated with the threshold for elevated NTD risk: >8 cases per 10,000 births) was widespread: 81.4% (75.0, 86.4). The predicted NTD risk nationally was 24.7 cases per 10,000 live births. RBC folate insufficiency and higher predicted NTD risk were more common among WRA living in urban areas or with higher education.

CONCLUSIONS

These findings highlight the importance of nutritional and NTD surveillance in Malawi and the opportunity for improving folate and vitamin B12 nutrition among Malawian WRA.

Preventing and Controlling Zinc Deficiency Across the Life Course: A Call to Action

Through diverse roles, zinc determines a greater number of critical life functions than any other single micronutrient. Beyond the well-recognized importance of zinc for child growth and resistance to infections, zinc has numerous specific roles covering the regulation of glucose metabolism, and growing evidence links zinc deficiency with increased risk of diabetes and cardiometabolic disorders. Zinc nutriture is, thus, vitally important to health across the life course. Zinc deficiency is also one of the most common forms of micronutrient malnutrition globally. A clearer estimate of the burden of health disparity attributable to zinc deficiency in adulthood and later life emerges when accounting for its contribution to global elevated fasting blood glucose and related noncommunicable diseases (NCDs). Yet progress attenuating its prevalence has been limited due, in part, to the lack of sensitive and specific methods to assess human zinc status. This narrative review covers recent developments in our understanding of zinc's role in health, the impact of the changing climate and global context on zinc intake, novel functional biomarkers showing promise for monitoring population-level interventions, and solutions for improving population zinc intake. It aims to spur on implementation of evidence-based interventions for preventing and controlling zinc deficiency across the life course. Increasing zinc intake and combating global zinc deficiency requires context-specific strategies and a combination of complementary, evidence-based interventions, including supplementation, food fortification, and food and agricultural solutions such as biofortification, alongside efforts to improve zinc bioavailability. Enhancing dietary zinc content and bioavailability through zinc biofortification is an inclusive nutrition solution that can benefit the most vulnerable individuals and populations affected by inadequate diets to the greatest extent.

A generic theory of change-based framework with core indicators for monitoring the effectiveness of large-scale food fortification programs in low- and middle-income countries

Large-scale food fortification (LSFF) programs are widely implemented in low- and middle-income countries (LMIC) to alleviate micronutrient deficiencies. However, these programs may not achieve the desired impact due to poor design or bottlenecks in program implementation. Monitoring and evaluation (M&E) frameworks and a set of agreed indicators can help to benchmark progress and to strengthen the evidence-base of effectiveness in a standardized way. We aimed to formulate recommendations towards core indicators for evaluating the effectiveness of LSFF programs with their associated metrics, methods, and tools (IMMT). For this, we used a multi-method iterative approach, including a mapping review of the literature, semi-structured interviews with international experts, compilation of a generic Theory of Change (ToC) framework for LSFF program delivery, and selection of IMMT for M&E of LSFF programs at key stages along the ToC delivery framework. Lastly, we conducted exploratory, qualitative interviews with key informants in Nigeria to explore experiences and perceptions related to the implementation of LSFF programs in Nigeria's context, and their opinion towards the proposed set of core IMMT. The literature search resulted in 14 published and 15 grey literature documents, from which we extracted a total of 41 indicators. Based on the available literature and interviews with international experts, we mapped a ToC delivery framework and selected nine core indicators at the output, outcome and impact level for M&E of the effectiveness of LSFF programs. Key informants in Nigeria revealed that the main bottlenecks for implementation of the proposed IMMT are related to the lack of technical capacity, equipment, laboratory infrastructure, and financial resources. In conclusion, we propose a set of nine core indicators for enabling comprehensive M&E of the effectiveness of LSFF programs in LMIC. This proposed set of core indicators can be used for further evaluation, harmonization and integration in national and international protocols for M&E of LSFF programs.

Aligning the Epidemiology of Malnutrition with Food Fortification: Grasp Versus Reach

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.

Evaluating equity dimensions of infant and child vitamin A supplementation programmes using Demographic and Health Surveys from 49 countries

OBJECTIVES

Vitamin A deficiency affects an estimated 29% of all children under 5 years of age in low/middle-income countries, contributing to child mortality and exacerbating severity of infections. Biannual vitamin A supplementation (VAS) for children aged 6-59 months can be a low-cost intervention to meet vitamin A needs. This study aimed to present a framework for evaluating the equity dimensions of national VAS programmes according to determinants known to affect child nutrition and assist programming by highlighting geographical variation in coverage.

METHODS

We used open-source data from the Demographic and Health Survey for 49 countries to identify differences in VAS coverage between subpopulations characterised by various immediate, underlying and enabling determinants of vitamin A status and geographically. This included recent consumption of vitamin A-rich foods, access to health systems and services, administrative region of the country, place of residence (rural vs urban), socioeconomic position, caregiver educational attainment and caregiver empowerment.

RESULTS

Children who did not recently consume vitamin A-rich foods and who had poorer access to health systems and services were less likely to receive VAS in most countries despite potentially having a greater vitamin A need. Differences in coverage were also observed when disaggregated by administrative regions (88% of countries) and urban versus rural residence (35% of countries). Differences in vitamin A coverage between subpopulations characterised by other determinants of vitamin A status varied considerably between countries.

CONCLUSION

VAS programmes are unable to reach all eligible infants and children, and subpopulation differences in VAS coverage characterised by various determinants of vitamin A status suggest that VAS programmes may not be operating equitably in many countries.

Local conceptions of the role of folate in neural tube defects in Zambia

OBJECTIVE

In sub-Saharan Africa, neural tube defects (NTDs) are the second most common birth defect, occurring eight times more frequently than in the US. The objective of this study was to assess baseline Zambian caregiver understanding of folate and NTDs and the effectiveness of an NTD prevention educational program.

METHODS

This prospective survey-based study included Zambian caregivers of children born with NTDs who completed pre- and post-educational program surveys between January 2020 and January 2021. The verbal survey was administered in English or local Zambian dialects. The 1-hour educational program administered by local Zambian research nurses sought to facilitate understanding of the direct relationship between prenatal folate supplementation and NTDs.

RESULTS

Sixty-one eligible caregivers with a median age of 20 (IQR 24-29) years completed the survey. Participants were predominantly from regions outside of Lusaka Province (68%, 41/60) rather than the capital city, Lusaka (32%, 19/60). Most had received prenatal care (91%, 57/61), and 80% (47/59) reported folate use in pregnancy. Of the mothers who took folate during pregnancy, 24% (11/45) reported use within the first 4 weeks after conception, while 76% (34/45) started thereafter. Myelomeningocele was the most common NTD (74%, 32/43), followed by meningocele (14%, 6/43). Prior to the educational program, 52% (29/56) of caregivers reported that NTDs were caused by a vitamin deficiency, which improved to 98% (55/56) after the program (p < 0.001). Furthermore, only 54% (33/61) of caregivers believed that folate should be taken before conception on the baseline survey evaluation, which improved to 95% (58/61, p < 0.001) after the program. All survey participants (58/58) found the educational session helpful.

CONCLUSIONS

This study found that a high proportion of Zambian caregivers had received prenatal care and even had taken folate during pregnancy, but none had taken it prior to pregnancy. An educational program effectively improved understanding about the role and timing of perinatal folate administration in NTD prevention. This result also emphasizes the need for folate fortification and folate education for not only mothers but also primary care providers.

Exploring the Complementarity of Fortification and Dietary Diversification to Combat Micronutrient Deficiencies: A Scoping Review

Achieving a balanced and diverse diet remains a challenge for many people, contributing to an ongoing burden of micronutrient deficiencies, particularly in low-income settings. Fortification or dietary diversification are common food-based approaches. We conducted a scoping review to: 1) find evidence on whether combined food-based strategies are more effective than single strategies, and 2) understand how strategies implemented together could complement each other to achieve optimal nutritional impact on populations. Peer-reviewed articles selected (n = 21) included interventions or observational studies (n = 13) and reviews (n = 8). We found little evidence of an added nutritional impact. On the other hand, it is apparent that fortification and dietary diversification target different types of settings (urban compared with rural) and foods (that is, low priced compared with highly priced). Further research is needed to understand the complementarity of these approaches and establish evidence of the effectiveness of combined strategies to foster policy adoption.

Fish and Fish-Based Products for Nutrition and Health in the First 1000 Days: A Systematic Review of the Evidence from Low and Middle-Income Countries

Fish provide essential nutrients for the critical window of growth and development in the first 1000 d of life and are thus an attractive option for inclusion in nutrition-sensitive and nutrition-specific programming. We conducted a systematic review of the evidence for fish and fish-based products for nutrition and health outcomes during the first 1000 d of life in low- and middle-income countries, searching the peer-reviewed and gray literature from 1999 to 2020. Databases included PubMed, Web of Science, Embase, ProQuest, and the Clinical Trials repository. Our search returned 1135 articles, 39 of which met the inclusion criteria. All studies were dual evaluated for risk of bias. Of the included studies, 18 measured maternal health and nutrition outcomes and 24 measured infant/child outcomes (3 measured both). Our search uncovered 10 impact evaluations, all of which measured consumption of fish or fish-based complementary food products in children aged 6-24 mo. We did not find strong evidence for fish consumption in children improving child growth from the impact evaluations; however, the studies were highly heterogeneous in their design and likely underpowered to detect an effect. Results from observational studies were mixed but provided evidence that adding fish to maternal and child diets is associated with improved nutrition outcomes, such as reducing the risk of anemia and improving vitamin D status. Given the nutrient richness of fish and the fact that production is often more environmentally friendly as compared with other animal source foods, more robust evidence is needed on the role of fish consumption in nutrition interventions to inform policy and programming recommendations in low- and middle-income countries.

Agronomic biofortification increases grain zinc concentration of maize grown under contrasting soil types in Malawi

Zinc (Zn) deficiency remains a public health problem in Malawi, especially among poor and marginalized rural populations, linked with low dietary intake of Zn due to consumption of staple foods that are low in Zn content. The concentration of Zn in staple cereal grain can be increased through application of Zn-enriched fertilizers, a process called agronomic biofortification or agro-fortification. Field experiments were conducted at three Agricultural Research Station sites to assess the potential of agronomic biofortification to improve Zn concentration in maize grain in Malawi as described in registered report published previously. The hypotheses of the study were (i) that application of Zn-enriched fertilizers would increase in the concentration of Zn in maize grain to benefit dietary requirements of Zn and (ii) that Zn concentration in maize grain and the effectiveness of agronomic biofortification would be different between soil types. At each site two different subsites were used, each corresponding to one of two agriculturally important soil types of Malawi, Lixisols and Vertisols. Within each subsite, three Zn fertilizer rates (1, 30, and 90 kg ha-1) were applied to experimental plots, using standard soil application methods, in a randomized complete block design. The experiment had 10 replicates at each of the three sites as informed by a power analysis from a pilot study, published in the registered report for this experiment, designed to detect a 10% increase in grain Zn concentration at 90 kg ha-1, relative to the concentration at 1 kg ha-1. At harvest, maize grain yield and Zn concentration in grain were measured, and Zn uptake by maize grain and Zn harvest index were calculated. At 30 kg ha-1, Zn fertilizer increased maize grain yields by 11% compared with nationally recommended application rate of 1 kg ha-1. Grain Zn concentration increased by 15% and uptake by 23% at the application rate of 30 kg ha-1 relative to the national recommendation rate. The effects of Zn fertilizer application rate on the response variables were not dependent on soil type. The current study demonstrates the importance of increasing the national recommendation rate of Zn fertilizer to improve maize yield and increase the Zn nutritional value of the staple crop.

Limited Supply of Protein and Lysine Is Prevalent among the Poorest Households in Malawi and Exacerbated by Low Protein Quality

We estimated dietary supplies of total and available protein and indispensable amino acids (IAAs) and predicted the risk of deficiency in Malawi using Household Consumption and Expenditure Survey data. More than half of dietary protein was derived from cereal crops, while animal products provided only 11%. The supply of IAAs followed similar patterns to that of total proteins. In general, median protein and IAA supplies were reduced by approximately 17% after accounting for digestibility, with higher losses evident among the poorest households. At population level, 20% of households were at risk of protein deficiency due to inadequate available protein supplies. Of concern was lysine supply, which was inadequate for 33% of households at the population level and for the majority of the poorest households. The adoption of quality protein maize (QPM) has the potential to reduce the risk of protein and lysine deficiency in the most vulnerable households by up to 12% and 21%, respectively.

Update on Analytical Methods and Research Gaps in the Use of Household Consumption and Expenditure Survey Data to Inform the Design of Food-Fortification Programs

The lack of nationally representative, individual-level dietary intake data has led researchers to increasingly turn to household-level data on food acquisitions and/or consumption to inform the design of food-fortification programs in low- and middle-income countries (LMICs). These nationally representative, household-level data come from household consumption and expenditure surveys (HCESs), which are collected regularly in many LMICs and are often made publicly available. Our objectives were to examine the utility of HCES data to inform the design of food-fortification programs and to identify best-practice methods for analyzing HCES data for this purpose. To this end, we summarized information needed to design fortification programs and assessed the extent to which HCES data can provide corresponding indicators. We concluded that HCES data are well suited to guide the selection of appropriate food vehicles, but because individual-level estimates of apparent nutrient intakes rely on assumptions about the intrahousehold distribution of food, more caution is advised when using HCES data to select the target micronutrient content of fortified foods. We also developed a checklist to guide analysts through the use of HCES data and, where possible, identified research-based, best-practice analytical methods for analyzing HCES data, including selecting the number of days of recall data to include in the analysis and converting reported units to standard units. More research is needed on how best to deal with composite foods, foods consumed away from home, and extreme values, as well as the best methods for assessing the adequacy of apparent intakes. Ultimately, we recommend sensitivity analyses around key model parameters, and the continual triangulation of HCES-based results with other national and subnational data on food availability, dietary intake, and nutritional status when designing food-fortification programs.

Soil and landscape factors influence geospatial variation in maize grain zinc concentration in Malawi

Dietary zinc (Zn) deficiency is widespread globally, and in particular among people in sub-Saharan Africa (SSA). In Malawi, dietary sources of Zn are dominated by maize and spatially dependent variation in grain Zn concentration, which will affect dietary Zn intake, has been reported at distances of up to ~ 100 km. The aim of this study was to identify potential soil properties and environmental covariates which might explain this longer-range spatial variation in maize grain Zn concentration. Data for maize grain Zn concentrations, soil properties, and environmental covariates were obtained from a spatially representative survey in Malawi (n = 1600 locations). Labile and non-labile soil Zn forms were determined using isotopic dilution methods, alongside conventional agronomic soil analyses. Soil properties and environmental covariates as potential predictors of the concentration of Zn in maize grain were tested using a priori expert rankings and false discovery rate (FDR) controls within the linear mixed model (LMM) framework that informed the original survey design. Mean and median grain Zn concentrations were 21.8 and 21.5 mg kg⁻¹, respectively (standard deviation 4.5; range 10.0–48.1). A LMM for grain Zn concentration was constructed for which the independent variables: soil pH_(water), isotopically exchangeable Zn (Zn_E), and diethylenetriaminepentaacetic acid (DTPA) extractable Zn (Zn_DTPA) had predictive value (p < 0.01 in all cases, with FDR controlled at < 0.05). Downscaled mean annual temperature also explained a proportion of the spatial variation in grain Zn concentration. Evidence for spatially dependent variation in maize grain Zn concentrations in Malawi is robust within the LMM framework used in this study, at distances of up to ~ 100 km. Spatial predictions from this LMM provide a basis for further investigation of variations in the contribution of staple foods to Zn nutrition, and where interventions to increase dietary Zn intake (e.g. biofortification) might be most effective. Other soil and landscape factors influencing spatially dependent variation in maize grain Zn concentration, along with factors operating over shorter distances such as choice of crop variety and agronomic practices, require further exploration beyond the scope of the design of this survey.