Large-scale food fortification (LSFF) is a cost-effective intervention that is widely implemented, but there is scope to further increase its potential. To identify gaps and opportunities, we first accessed the Global Fortification Data Exchange (GFDx) to identify countries that could benefit from new fortification programs. Second, we aggregated Fortification Assessment Coverage Toolkit (FACT) survey data from 16 countries to ascertain LSFF coverage and gaps therein. Third, we extended our narrative review to assess current innovations. We identified 84 countries as good candidates for new LSFF programs. FACT data revealed that the potential of oil/ghee and salt fortification is not being met due mainly to low coverage of adequately fortified foods (quality). Wheat, rice and maize flour fortification have similar quality issues combined with lower coverage of the fortifiable food at population-level (<50%). A four-pronged strategy is needed to meet the unfinished agenda: first, establish new LSFF programs where warranted; second, systems innovations informed by implementation research to address coverage and quality gaps; third, advocacy to form new partnerships and resources, particularly with the private sector; and finally, exploration of new fortificants and vehicles (e.g. bouillon cubes; salt fortified with multiple nutrients) and other innovations that can address existing challenges.

Background: There has been tremendous progress over the past 25 years to control iodine deficiency disorders (IDDs) through universal salt iodization (USI). In 2019, using the median urinary iodine concentration (MUIC), only 19 countries in the world are classified as iodine deficient; in contrast in 1993, using the total goiter rate (TGR), 113 countries were classified as iodine deficient. However, few analyses have tried to quantify the global health and economic benefits of USI programs, and the shift from TGR to MUIC as the main indicator of IDDs complicates assessment of progress. Methods: We used a novel approach to estimate the impact of USI on IDDs, applying a regression model derived from observational data on the relationship between the TGR and the MUIC from 24 countries. The model was used to generate hypothetical national TGR values for 2019 based on current MUIC data. TGR in 1993 and modeled TGR in 2019 were then compared for 139 countries, and using consequence modeling, the potential health and economic benefits realized between 1993 and 2019 were estimated. Results: Based on this approach, the global prevalence of clinical IDDs (as assessed by the TGR) fell from 13.1% to 3.2%, and 720 million cases of clinical IDDs have been prevented by USI (a reduction of 75.9%). USI has significantly reduced the number of newborns affected by IDDs, with 20.5 million cases prevented annually. The resulting improvement in cognitive development and future earnings suggest a potential global economic benefit of nearly $33 billion. However, 4.8 million newborns will be affected by IDDs in 2019, who will experience life-long productivity losses totaling a net present value of $12.5 billion. Conclusions: The global improvements in iodine status over the past 25 years have resulted in major health and economic benefits, mainly in low- and middle-income countries. Efforts should now focus on sustaining this achievement and expanding USI to reach the continuing large number of infants who remain unprotected from IDDs.

Objective: The main indicator adopted to track universal salt iodization has been the coverage of adequately iodized salt in households. Rapid test kits (RTK) have been included in household surveys to test the iodine content in salt. However, laboratory studies of their performance have concluded that RTK are reliable only to distinguish between the presence and absence of iodine in salt, but not to determine whether salt is adequately iodized. The aim of the current paper was to examine the performance of RTK under field conditions and to recommend their most appropriate use in household surveys.Design: Standard performance characteristics of the ability of RTK to detect the iodine content in salt at 0 mg/kg (salt with no iodine), 5 mg/kg (salt with any added iodine) and 15 mg/kg (‘adequately’ iodized salt) were calculated. Our analysis employed the agreement rate (AR) as a preferred metric of RTK performance.Setting/Subjects: Twenty-five data sets from eighteen population surveys which assessed household iodized salt by both the RTK and a quantitative method (i.e. titration or WYD Checker) were obtained from Asian (nineteen data sets), African (five) and European (one) countries.Results: In detecting iodine in salt at 0 mg/kg, the RTK had an AR>90 % in eight of twenty-three surveys, while eight surveys had an AR90 %.Conclusions: The RTK is not suited for assessment of adequately iodized salt coverage. Quantitative assessment, such as by titration or WYD Checker, is necessary for estimates of adequately iodized salt coverage.

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.

Could DFS help prevent iron deficiency and anemia? Studies in controlled settings (efficacy) demonstrate that double-fortified salt (DFS; iron added to iodized salt) reduces the prevalence of anemia and iron deficiency anemia. Studies in program settings (effectiveness) are limited and reported differing levels of DFS coverage, resulting in mixed evidence of impact on anemia. What iron formulations are available and how do they affect iodized salt? Ferrous sulfate and encapsulated ferrous fumarate (both with various enhancers and/or coating materials) are the main iron formulations currently in use for DFS. Adding iron to iodized salt may lead to adverse changes in the product, specifically discoloration and losses in iodine content. These changes are greatest when the iodized salt used in DFS production is of low quality (e.g., contain impurities, has high moisture, and is of large crystal size). DFS requires iodized salt of the highest quality and a high-quality iron formulation in order to minimize adverse sensory changes and iodine losses. Appropriate packaging of iodized salt is also important to prevent losses. What is known about the minimum requirements to manufacture DFS? DFS producers must use high-quality refined iodized salt meeting the minimum standards for DFS production (which is higher than standards for salt intended for iodization alone), and an iron formulation for which there are rigid quality-assurance measures to ensure consistent quality and blending techniques. The actual proportion of iodized salt meeting the stringent requirements necessary for DFS production is unclear, but likely to be low in many countries, especially those with fragmented salt industries and a low proportion of industrially produced salt. What are the financial implications of adding iron to iodized salt? As a result of higher input costs both for input salt and the iron compound, DFS is more expensive to produce than iodized salt and thus has a higher production cost. Various grades of iodized salt are produced and consumed in different sectors of the market. Experience in India indicates that, on average, producing DFS costs 31-40 US dollars/metric ton or 0.03-0.04 US dollars/kg more than high-quality refined iodized salt. The exact impact of this production-level cost difference on profit margins and consumer price is specific to the conditions of different salt markets. Factors such as transport costs, customary wholesale and retail mark-ups, and taxes all vary greatly and need to be assessed on a case by case basis. Is DFS in alignment with salt-reduction efforts? The WHO has long recognized that salt iodization is an important public health intervention to achieve optimal iodine nutrition and is compatible with salt-reduction goals. Fortification of salt (with any nutrient) should not be used to justify or encourage an increase in salt intake to the public. Any effort to expand salt fortification to other nutrients should be done in close consultation with WHO and those working on salt reduction. What has been the experience with DFS delivery under different platforms? To date, DFS has been introduced into the retail market and in social safety net (primarily in India) programs, but sensory changes in DFS have been raised as concerns. The higher price for DFS has limited expansion in the retail market. In social safety net programs where the cost of DFS is subsidized for beneficiaries, programs must consider long-term resourcing for sustainability. Overall: The optimal production and delivery of DFS are still under development, as many challenges need to be overcome. There is a beneficial impact on hemoglobin in efficacy trials. Thus, if those conditions can be replicated in programs or the technology can be adapted to better fit current production and delivery realities, DFS may provide an effective contribution in countries that need additional food-fortification vehicles to improve iron intake.

Universal salt iodisation (USI) was introduced in Sri Lanka in 1995. Since then, four national iodine surveys have assessed the iodine nutrition status of the population. We retrospectively reviewed median urine iodine concentration (mUIC) and goitre prevalence in 16,910 schoolchildren (6–12 years) in all nine provinces of Sri Lanka, the mUIC of pregnant women, drinking-water iodine level, and the percentage of households consuming adequately (15 mg/kg) iodised salt (household salt iodine, HHIS). The mUIC of schoolchildren increased from 145.3 µg/L (interquartile range (IQR) = 84.6–240.4) in 2000 to 232.5 µg/L (IQR = 159.3–315.8) in 2016, but stayed within recommended levels. Some regional variability in mUIC was observed (178.8 and 297.3 µg/L in 2016). There was positive association between mUIC in schoolchildren and water iodine concentration. Goitre prevalence to palpation was a significantly reduced from 18.6% to 2.1% (p < 0.05). In pregnant women, median UIC increased in each trimester (102.3 (61.7–147.1); 217.5 (115.6–313.0); 273.1 (228.9–337.6) µg/L (p = 0.000)). We conclude that the introduction and maintenance of a continuous and consistent USI programme has been a success in Sri Lanka. In order to sustain the programme, it is important to retain monitoring of iodine status while tracking salt-consumption patterns to adjust the recommended iodine content of edible salt.