Applying Zinc Nutrient Reference Values as Proposed by Different Authorities Results in Large Differences in the Estimated Prevalence of Inadequate Zinc Intake by Young Children and Women and in Cameroon.

Nutrient reference values (NRVs) for zinc set by several expert groups differ widely and may affect the predicted prevalence of inadequate zinc intake. We examined this possibility using NRVs published by four different authorities and nationally representative dietary intake data collected among children aged 12-59 months and women in Cameroon. Usual zinc intake was estimated from 24 h recall data using the National Cancer Institute method. Prevalences of total zinc intake below the dietary requirement and of "absorbable zinc intake" below the physiological requirement were estimated using NRVs published by the World Health Organization (WHO), US Institute of Medicine (IOM), International Zinc Nutrition Consultative Group (IZiNCG), and European Food Safety Authority (EFSA). The prevalence of inadequate zinc intake ranged from 10% (IZiNCG-physiological requirement, 95% CI 7-13%) to 81% (EFSA-physiological requirement, 95% CI 78-84%) among children and 9% (WHO-physiological requirement, 95% CI 8-11.0%) to 94% (IOM-physiological requirement, 95% CI 92-95%) among women These differences in the prevalence of inadequate intake translated into sizeable differences in the predicted benefit and cost-effectiveness of zinc fortification programs. Depending on the NRVs applied, assessments differ regarding the need for and design of zinc fortification programs. Efforts are needed to harmonize NRVs for zinc.

Predicted Effects and Cost-Effectiveness of Wheat Flour Fortification for Reducing Micronutrient Deficiencies, Maternal Anemia, and Neural Tube Defects in Yaoundé and Douala, Cameroon.

BACKGROUND: Policy makers aiming to reduce micronutrient deficiencies (MNDs) and their health effects must choose among alternative definitions of impact when evaluating cost-effectiveness. OBJECTIVE: Estimate the cost-effectiveness of a mandatory wheat flour fortification program for reducing cases of MNDs (iron, zinc, folate, vitamin B12), anemia and neural tube defects (NTDs) averted, and disability-adjusted life years (DALYs) averted in urban Cameroon. METHODS: A 13-year predictive model was developed, including a 3-year start-up period and 10 years of program activity. Costs were estimated using historical program budgets. Effects were calculated based on observed changes in prevalence of MND and anemia 1 year postfortification and predicted reductions in NTDs based on NTD burden and wheat flour intake. Total DALYs averted were estimated for anemia and NTDs. RESULTS: The program cost ∼$2.4 million over 13 years and averted an estimated ∼95 000 cases of maternal anemia and ∼83 500 cases of iron deficiency among children after 1 year. Cost/case-year averted for MNDs ranged from $0.50 for low plasma folate to $3.30 for iron deficiency and was $2.20 for maternal anemia. The program was predicted to avert 1600 cases of NTDs over 10 years at ∼$1500 per case averted. Estimated cost/DALY averted was $50 for NTDs and $115 for anemia. CONCLUSIONS: In Cameroon, cost-effectiveness of wheat flour fortification varied by the measure of impact employed, but was classified as "very cost-effective" for all outcomes using World Health Organization criteria. Policy makers and their advisors must determine how best to use information on program costs and benefits to inform their decisions.

Review of Existing Models to Predict Reductions in Neural Tube Defects Due to Folic Acid Fortification and Model Results Using Data from Cameroon.

Several models have been developed to predict the effects of folic acid fortification programs on prevention of neural tube defects (NTDs), but each relies on different assumptions and data inputs. We identified and reviewed 7 models that predict the effects of folic acid intake or status on NTD risk. We applied 4 of these models [the original and a modified version of the Lives Saved Tool (LiST) and models developed by Arth et al. and Wald et al.] to predict the effect of folic acid fortification of wheat flour on reduction of NTDs using national survey data from Cameroon. The estimated percentage of NTDs averted due to fortified wheat flour (5.0 µg folic acid/g flour) varied by predictive model, with a 21-31% reduction in LiST to 83% in Arth's model, and 15% in Wald's model. As the simulated fortification level was increased from 1.0 to 7.0 µg folic acid/g flour, the pattern of change in estimated numbers of NTDs averted differed due to different model assumptions: the number of NTDs averted increased and then reached a plateau in the modified LiST model (as would be expected in real-world conditions), increased sharply in Arth's model, and increased continuously in Wald's model. This wide variation in predicted effects, and implausible results in some cases, undermines the models' utility for users of model outputs. Concurrent collection of dietary and biomarker data, including plasma and RBC folate concentrations, and NTD outcomes, is necessary to validate these models and monitor change in folic acid intake, folate-related biomarkers, and reduced NTD risk due to fortification. In the meantime, models based on erythrocyte folate concentration are recommended, based on biological plausibility and consistency with empirical evidence. Where erythrocyte folate data are unavailable, sensitivity analyses (using several models) could be conducted to examine the range of possible outcomes.

Within-Person Variation in Nutrient Intakes across Populations and Settings: Implications for the Use of External Estimates in Modeling Usual Nutrient Intake Distributions.

Determining the proportion of a population at risk of inadequate or excessive nutrient intake is a crucial step in planning and managing nutrition intervention programs. Multiple days of 24-h dietary intake data per subject allow for adjustment of modeled usual nutrient intake distributions for the proportion of total variance in intake attributable to within-individual variation (WIV:total). When only single-day dietary data are available, an external adjustment factor can be used; however, WIV:total may vary by population, and use of incorrect WIV:total ratios may influence the accuracy of prevalence estimates and subsequent program impacts. WIV:total values were compiled from publications and from reanalyses of existing datasets to describe variation in WIV:total across populations and settings. The potential impact of variation in external WIV:total on estimates of prevalence of inadequacy was assessed through simulation analyses using the National Cancer Institute 1-d method. WIV:total values were extracted from 40 publications from 24 countries, and additional values were calculated from 15 datasets from 12 nations. Wide variation in WIV:total (from 0.02 to 1.00) was observed in publications and reanalyses. Few patterns by population characteristics were apparent, but WIV:total varied by age in children (< vs. >1 y) and between rural and urban settings. Simulation analyses indicated that estimates of the prevalence of inadequate intake are sensitive to the selected ratio in some cases. Selection of an external WIV:total estimate should consider comparability between the reference and primary studies with regard to population characteristics, study design, and statistical methods. Given wide variation in observed ratios with few discernible patterns, the collection of ≥2 days of intake data in at least a representative subsample in population dietary studies is strongly encouraged. In the case of single-day dietary studies, sensitivity analyses are recommended to determine the robustness of prevalence estimates to changes in the variance ratio.

Micronutrient Fortification of Commercially Available Biscuits Is Predicted to Have Minimal Impact on Prevalence of Inadequate Micronutrient Intakes: Modeling of National Dietary Data From Cameroon.

BACKGROUND: Voluntarily fortified snack products are increasingly available but are not necessarily formulated to meet known dietary nutrient gaps, so potential impacts on population micronutrient intake adequacy are uncertain. OBJECTIVES: We modeled the impacts of hypothetical micronutrient-fortified biscuits on inadequate micronutrient intake in children and women of reproductive age (WRA) in Cameroon. METHODS: In a nationally representative survey stratified by macro-region (North, South, and Yaoundé/Douala), 24-h dietary recall data were collected from 883 children aged 12-59 mo and from 912 WRA. We estimated usual nutrient intake by the National Cancer Institute method for vitamin A, folate, vitamin B-12, zinc, and iron. We simulated the impact of biscuit fortification on prevalence of micronutrient intake below the estimated average requirement, given observed biscuit consumption, in the presence and absence of large-scale food fortification (LSFF) programs. RESULTS: Biscuit consumption in the prior 24-h by children and WRA, respectively, ranged from 4.5% and 1.5% in the South, to 20.7% and 5.9% in Yaoundé/Douala. In the absence of LSFF programs, biscuits fortified with retinol (600 µg/100 g), folic acid (300 µg/100 g), and zinc (8 mg/100 g) were predicted to reduce the prevalence of inadequacy among children by 10.3 ± 4.4, 13.2 ± 4.2, and 12.0 ± 6.1 percentage points, respectively, in Yaoundé/Douala. However, when existing vitamin A-fortified oil, and folic acid-fortified and zinc-fortified wheat flour programs were considered, the additional impacts of fortified biscuits were reduced substantially. Micronutrient-fortified biscuits were predicted to have minimal impact on dietary inadequacy in WRA, with or without LSFF programs. CONCLUSIONS: Given observed patterns of biscuit consumption in Cameroon, biscuit fortification is unlikely to reduce dietary inadequacy of studied micronutrients, except possibly for selected nutrients in children in urban areas in the absence of LSFF programs. As voluntary fortification becomes increasingly common, modeling studies could help guide efforts to ensure that fortified products align with public health goals.

Strategies to achieve adequate vitamin A intake for young children: options for Cameroon.

Meeting children's vitamin A (VA) needs remains a policy priority. Doing so efficiently is a fiscal imperative and protecting at-risk children during policy transitions is a moral imperative. Using the Micronutrient Intervention Modeling tool and data for Cameroon, we predict the impacts and costs of alternative VA intervention programs, identify the least-cost strategy for meeting targets nationally, and compare it to a business-as-usual (BAU) strategy over 10 years. BAU programs effectively cover ∼12.8 million (m) child-years (CY) and cost ∼$30.1 m; ∼US$2.34 per CY effectively covered. Improving the VA-fortified oil program, implementing a VA-fortified bouillon cube program, and periodic VA supplements (VAS) in the North macroregion for 3 years effectively cover ∼13.1 m CY at a cost of ∼US$9.5 m, or ∼US$0.71 per CY effectively covered. The tool then identifies a sequence of subnational policy choices leading from the BAU toward the more efficient strategy, while addressing VA-attributable mortality concerns. By year 4, fortification programs are predicted to eliminate inadequate VA intake in the South and Cities macroregions, but not the North, where VAS should continue until additional delivery platforms are implemented. This modeling approach offers a concrete example of the strategic use of data to follow the Global Alliance for VA framework and do so efficiently.

Replacing iron-folic acid with multiple micronutrient supplements among pregnant women in Bangladesh and Burkina Faso: costs, impacts, and cost-effectiveness.

Consumption of multiple micronutrient supplements (MMS) during pregnancy offers additional benefits compared with iron-folic acid (IFA) supplementation, but the tablets are more expensive. We estimated the effects, costs, and cost-effectiveness of hypothetically replacing IFA supplements with MMS for 1 year in Bangladesh and Burkina Faso. Using baseline demographic characteristics from LiST and effect sizes from a meta-analysis, we estimated the marginal effects of replacing IFA with MMS on mortality, adverse birth outcomes, and disability-adjusted life years (DALYs) averted. We calculated the marginal tablet costs of completely replacing MMS with IFA (assuming 180 tablets per covered pregnancy). Replacing IFA with MMS could avert over 15,000 deaths and 30,000 cases of preterm birth annually in Bangladesh and over 5000 deaths and 5000 cases of preterm birth in Burkina Faso, assuming 100% coverage and adherence. We estimated the cost per death averted to be US$175-185 in Bangladesh and $112-125 in Burkina Faso. Cost per DALY averted ranged from $3 to $15, depending on the country and consideration of subgroup effects. Our estimates suggest that this policy change would cost-effectively save lives and reduce life-long disabilities. Improvements in program delivery and supplement adherence would be expected to improve the cost-effectiveness of replacing IFA with MMS.

Prenatal and Postnatal Supplementation with Lipid-Based Nutrient Supplements Reduces Anemia and Iron Deficiency in 18-Month-Old Bangladeshi Children: A Cluster-Randomized Effectiveness Trial.

Background: Anemia, iron deficiency (ID), and iron deficiency anemia (IDA) among young children are public health concerns in developing countries. Objective: We evaluated the effects of small-quantity lipid-based nutrient supplements (LNSs) and micronutrient powder (MNP) on anemia, ID, and IDA in 18-mo-old Bangladeshi children. Methods: We enrolled 4011 pregnant women in a cluster-randomized effectiveness trial with 4 arms-1) LNS-LNS: LNSs (including 20 mg Fe) for women daily during pregnancy and 6 mo postpartum and LNSs (including 9 mg Fe) for children daily from 6 to 24 mo of age (LNS-C); 2) IFA-LNS: iron (60 mg) and folic acid (IFA) for women daily during pregnancy and every other day for 3 mo postpartum and LNS-C for children; 3) IFA-MNP: IFA for women, and MNP (including 10 mg Fe) for children daily from 6 to 24 mo; and 4) IFA-Control: IFA for women and no child supplement. Hemoglobin, serum ferritin, and soluble transferrin receptor (sTfR) were assessed in a subsample of children (n = 1121) at 18 mo to identify anemia (hemoglobin <110g/L), ID (ferritin <12 µg/L or sTfR >8.3 mg/L), and IDA. Data were analyzed with the use of mixed-effects modeling. Results: Compared with the IFA-Control arm, hemoglobin was higher in the LNS-LNS and IFA-LNS arms and ferritin was higher and sTfR was lower in the LNS-LNS, IFA-LNS, and IFA-MNP arms; LNS-LNS children had reduced odds of anemia (OR: 0.46; 95% CI: 0.25, 0.84), high sTfR (OR: 0.47; 95% CI: 0.29, 0.73), and ID (OR: 0.45; 95% CI: 0.28, 0.71); and all 3 groups had lower odds of low ferritin [corrected for inflammation; OR (95% CI)-LNS-LNS: 0.29 (0.13, 0.63); IFA-LNS: 0.25 (0.11, 0.59); and IFA-MNP: 0.37 (0.18, 0.76)] and IDA [LNS-LNS: 0.35 (0.18, 0.67); IFA-LNS: 0.45 (0.24,0.85); and IFA-MNP: 0.47 (0.26, 0.87)]. Conclusions: Home fortification using LNSs or MNP reduced IDA in 18-mo-old Bangladeshi children. The provision of LNSs in both pregnancy and childhood also reduced child anemia and ID. These findings are relevant to programs targeting similar populations. This trial was registered at www.clinicaltrials.gov as NCT01715038.

Eating down or simply eating less? The diet and health implications of these practices during pregnancy and postpartum in rural Bangladesh.

OBJECTIVE: To: (i) determine the prevalence of self-reported eating less and eating down during early and late pregnancy and postpartum, and explore risk factors associated with eating less; (ii) examine the association between eating less and diet quality; and (iii) determine the association between eating less and weight gain during pregnancy. DESIGN: Data were collected longitudinally from a cohort of women participating in a community health programme. Diet was assessed at three time points (≤20 weeks' gestation, 36 weeks' gestation, 6 months' postpartum), body weight was measured during study enrolment (≤20 weeks' gestation) and at 36 weeks' gestation, and information about the woman and her household was collected at enrolment. SETTING: The Rang-Din Nutrition Study in the Rangpur and Dinajpur districts of Bangladesh. SUBJECTS: Women (n 4011). RESULTS: The prevalence of self-reported eating less differed by time point (75·9 % in early pregnancy, 38·8 % in late pregnancy, 7·4 % postpartum; P<0·001). The most common reason for eating less across all time periods was food aversion or loss of appetite. Women who reported eating less in late pregnancy had consumed animal-source foods less frequently in the preceding week than women who reported eating more (mean (sd): 11·7 (7·4) v. 14·8 (9·2) times/week; P<0·001) and had lower weekly weight gain than women who reported eating more (mean (se): 0·27 (0·004) v. 0·33 (0·004) kg/week; P<0·001). CONCLUSIONS: Eating less has negative implications with respect to diet quality and pregnancy weight gain in this context.

Maternal Supplementation with Small-Quantity Lipid-Based Nutrient Supplements Compared with Multiple Micronutrients, but Not with Iron and Folic Acid, Reduces the Prevalence of Low Gestational Weight Gain in Semi-Urban Ghana: A Randomized Controlled Trial.

Background: It is unclear whether maternal supplementation with small-quantity lipid-based nutrient supplements (SQ-LNSs; 118 kcal/d) affects maternal weight.Objective: We compared several secondary anthropometric measures between 3 groups of women in the iLiNS (International Lipid-based Nutrient Supplements)-DYAD trial in Ghana.Methods: Women (n = 1320; <20 wk of gestation) were randomly assigned to receive 60 mg Fe + 400 µg folic acid/d (IFA), 18 vitamins and minerals/d [multiple micronutrients (MMNs)], or 20 g SQ-LNSs with 22 micronutrients/d (LNS) during pregnancy and a placebo (200 mg Ca/d), MMNs, or SQ-LNSs, respectively, for 6 mo postpartum. Weight, midupper arm circumference (MUAC), and triceps skinfold (TSF) thickness at 36 wk of gestation and 6 mo postpartum were analyzed, as were changes from estimated prepregnancy values. We assessed the adequacy of estimated gestational weight gain (GWG) by using Institute of Medicine (IOM) and International Fetal and Newborn Growth Standards for the 21st Century (INTERGROWTH-21st) guidelines.Results: The estimated prepregnancy prevalence of overweight or obesity was 38.5%. By 36 wk of gestation, women (n = 1015) had a mean ± SD weight gain of 7.4 ± 3.7 kg and changes of -1.0 ± 1.7 cm in MUAC and -2.8 ± 4.1 mm in TSF thickness. The LNS group had a lower prevalence of inadequate GWG on the basis of IOM guidelines (57.4%) than the MMN (67.2%) but not the IFA (63.1%) groups (P = 0.030), whereas the prevalence of adequate (26.9% overall) and excessive (10.4% overall) GWG did not differ by group. The percentages of normal-weight women (in kg/m2: 18.5 < body mass index < 25.0; n = 754) whose GWG was less than the third centile of the INTERGROWTH-21st standards were 23.0%, 28.7%, and 28.5% for the LNS, MMN, and IFA groups, respectively (P = 0.36). At 6 mo postpartum, the prevalence of overweight or obesity was 45.3%, and the risk of becoming overweight or obese did not differ by group.Conclusion: SQ-LNS supplementation is one potential strategy to address the high prevalence of inadequate GWG in women in settings similar to Ghana, without increasing the risk of excessive GWG. This trial was registered at clinicaltrials.gov as NCT00970866.

Program changes are effective and cost-effective in increasing the amount of oil used in preparing corn soy blend porridge for treatment of moderate acute malnutrition in Malawi.

Corn Soy Blend (CSB) porridge is commonly prepared with oil for treatment of moderate acute malnutrition (MAM). A recent review recommended that 30 g of oil be used with 100 g of CSB to increase energy density and micronutrient absorption. This study assessed the effectiveness and cost-effectiveness of program changes aimed at achieving that target oil:CSB ratio in prepared porridge. Caregivers of children in MAM supplementary feeding programs were assigned to three groups: a control group received monthly rations of 1 L oil, 8 kg CSB in bulk, and social and behavior change communication (SBCC); intervention groups received 2.6 L oil, 8 kg CSB provided either in bulk (Group 1) or four 2-kg packages with printed messages (Group 2), and enhanced SBCC emphasizing the target oil:CSB ratio. Compared to the control, both intervention groups had higher mean added oil per 100 g CSB (18 g, p < 0.01, and 13 g, p= 0.04, higher in groups 1 and 2, respectively), and greater odds of meeting or exceeding the target ratio (28.4, p< 0.01, and 12.7, p= 0.02, in groups 1 and 2, respectively). Cost per caregiver reaching the target ratio was most favorable in Group 1 ($391 in Group 1, $527 in Group 2, and $1,666 in the control). Enhanced SBCC combined with increased oil ration resulted in increased use of oil in CSB porridge in a supplementary feeding program. Modified packaging did not improve effectiveness. However, both interventions were more cost-effective than standard programming.

Adherence to recommendations on lipid-based nutrient supplement and iron and folic acid tablet consumption among pregnant and lactating women participating in a community health programme in northwest Bangladesh.

Limited knowledge exists on sustained adherence to small-quantity lipid-based nutrient supplements for pregnant and lactating women (LNS-PL) and how this compares with that of other prenatal supplements. To address these gaps, a random subsample of women (n = 360) during pregnancy, early (6- to 12-week post-partum) and late (12- to 24-week post-partum) lactation, from an ongoing effectiveness trial in Bangladesh, was selected for in-home interviews about LNS-PL or iron/folic acid (IFA) use and preferences. Prevalence of high adherence (≥70% of the recommendation) based on self-reported supplement consumption was 67%, 68% and 81% among LNS-PL recipients during pregnancy, early and late lactation, and was 87% and 71% among IFA recipients during pregnancy and early lactation, respectively (P = 0.044). Programmatic factors (e.g. distribution and visits by programme staff) were consistently statistically significantly associated with reported high adherence. Among LNS-PL recipients, high overall supplement acceptability score [odds ratio (OR): 8.62; 95% confidence interval (CI) 3.53, 20.83] and use of reminder techniques (OR: 4.41; 95%CI 1.65, 11.76) were positively associated, and reported vomiting at enrollment was negatively associated (OR: 0.34; 95%CI 0.14, 0.80), with reported high adherence. Selected women (n = 16) and key informants (n = 18) participated in in-depth interviews about perceptions and acceptability of LNS-PL. Women perceived benefits of taking LNS-PL, but some faced barriers to consumption including aversion to odour and taste during pregnancy, forgetfulness and disruptions in supply. To achieve high adherence, results from this study suggest that maternal supplementation programmes should focus on programmatic barriers and consider incorporating reminder techniques. Organoleptic acceptability of LNS-PL, particularly during pregnancy, may also need to be addressed.

Estimating the Effective Coverage of Programs to Control Vitamin A Deficiency and Its Consequences Among Women and Young Children in Cameroon.

BACKGROUND: To compare the cost-effectiveness of nutrition programs, the anticipated nutritional benefits of each intervention must be expressed using a common metric. OBJECTIVE: We present the methodology for estimating the benefits of vitamin A (VA)-related interventions among women and children in Cameroon. METHODS: We estimated "reach" (proportion of the population that receives a program), "coverage" (proportion that is deficient and receives a program), and "effective coverage" (proportion that "converts" from inadequate to adequate VA intake following an intervention) using dietary data collected during a national survey in 3 macro-regions of Cameroon (North, South, and Yaoundé/Douala). Effective coverage of programs such as (bio)fortification and micronutrient powders was estimated by adding the dietary VA contributed by the intervention to baseline VA intakes, including the contribution of increased maternal VA intake to infant VA intake through increases in breast milk VA. For interventions that provide VA-related benefits through other pathways (eg, periodic high-dose VA supplements and deworming), we developed alternative methods of estimating "daily VA intake equivalents. " RESULTS: Baseline VA intakes and intervention reach varied by geographic macro-region. On average, estimates of program reach were greater than the effective coverage estimates by ∼50%. Effective coverage varied by intervention package and macro-region, ranging from <20 000 (deworming, Yaoundé/Douala) to >400 000 (micronutrient powder or VA supplement, North) children effectively covered per year. CONCLUSION: These estimates of effective coverage, along with macro-region-specific information on the costs of each intervention package, serve as inputs into an economic optimization model to identify the most cost-effective package of VA interventions for each macro-region of Cameroon.

Measuring the Costs of Vitamin A Interventions: Institutional, Spatial, and Temporal Issues in the Context of Cameroon.

BACKGROUND: To address vitamin A (VA) deficiency, an array of interventions have been developed for increasing VA status among young children. With numerous possible combinations of interventions, however, comes the need to take decisions regarding which intervention or combination of interventions is most cost effective for achieving VA deficiency reduction targets. METHODS: Detailed intervention-specific, "macro-region"-level data in Cameroon are used to generate estimates of the costs associated with delivering VA to children aged 6 to 59 months. RESULTS: In Cameroon, our estimates of costs per effectively-covered child (ie, children at risk of inadequate intake of VA who are exposed to an intervention and who achieve adequate intake) each year (2 rounds of Child Health Days [CHDs]) were US$3.31 for VA supplements. VA fortification of edible oil and bouillon cube was US$2.95 and US$2.41, respectively, per child effectively covered per year, and biofortification of maize was US$5.30 per child effectively covered per year. Combinations of interventions could reduce costs (eg, delivering additional interventions that affect VA status through the CHDs). Spatial differences in costs within Cameroon were also evident, for example, delivering high-dose VA capsules through CHDs leads to a cost of US$0.77 per child reached in the northern regions compared to US$1.40 per child reached in the southern regions. CONCLUSION: The costs associated with alternative VA interventions in Cameroon differ spatially, temporally, and in their cost-effectiveness. Choosing the appropriate combination of interventions can produce a more efficient portfolio of interventions to address VA deficiencies and VA-related deaths.

An Economic Optimization Model for Improving the Efficiency of Vitamin A Interventions: An Application to Young Children in Cameroon.

BACKGROUND: Vitamin A (VA) intervention programs in developing countries do not generally consider spatial differences in needs or in intervention costs. New data from Cameroon reveal nonuniform spatial distributions of VA deficiency among young children and of costs of some of the programs designed to address them. METHODS: We develop a spatially explicit, intertemporal economic optimization tool that makes use of subnational dietary intake data and VA intervention program costs to identify more efficient sets of interventions to improve VA nutrition among young children aged 6 to 59 months in Cameroon. RESULTS: The model suggests substantial changes in the composition and geographic foci of VA intervention programs vis-à-vis a business-as-usual scenario. National VA-fortified edible oil and bouillon cube programs are cost-effective, even when start-up costs are considered. High-dosage VA supplementation delivered via Child Health Days is most cost-effective in the North macro-region, where needs are greatest and the cost per child effectively covered is lowest. Overall, the VA intervention programs suggested by the optimization model are approximately 44% less expensive, with no change in the total number of children effectively covered nationwide. CONCLUSIONS: The VA intervention programs should consider spatial and temporal differences in needs and in the expected benefits and costs of alternative VA interventions. Doing so will require spatially disaggregated strategies and the data and political will to support them, longer planning time horizons than are currently used in most developing countries, and long-term funding commitments.

Use of Optimization Modeling for Selecting National Micronutrient Intervention Strategies: An Example Based on Potential Programs for Control of Vitamin A Deficiency in Cameroon.

Vitamin and mineral (micronutrient [MN]) deficiencies are common in lower income countries, especially among young children and women of reproductive age. These deficiencies are cause for serious concern because of their high prevalence and their associated complications, which include depressed immune function and increased risk and severity of infections, impaired neurocognitive development, and anemia, which together result in elevated mortality and reduced human productive capacity. A broad range of different intervention strategies are available to control MN deficiencies. At present, these interventions are usually implemented at a national scale through different public and private sector entities, often with little coordination. We have developed a set of models based on the estimated ability of different interventions to achieve effective coverage and the necessary financial resources required to deploy these interventions. The models provide a unified and transparent framework for considering different options using the common indicator of effective coverage. More specifically, information on nutritional benefits and costs are analyzed using an economic optimization model to identify the mix of interventions that could be delivered to specific target groups in particular geographic areas to achieve a desired level of effective coverage at lowest cost. Alternatively, these optimization models can be developed to identify the combination of interventions needed to achieve the maximum effective coverage, given specified budgetary limitations. The results of these models can be useful input into policy-making processes. To introduce this analytical approach, the set of papers in this volume addresses the problem of vitamin A deficiency among young children in Cameroon.