Fortifying staple foods could dramatically reduce global nutrient deficiencies at minimal cost, but disparities still exist and the risks of overconsumption highlight the need for smarter and more balanced nutrition strategies.
Research: The impact of large-scale food fortification programs on micronutrient deficiencies and the cost of implementing them: A modeling analysis. Image credit: udra11/Shutterstock.com
Expanding guideline-based food fortification programs is a cost-effective intervention that can reduce the prevalence of micronutrient deficiencies, particularly iron and iodine deficiencies, according to a modeling study published in . lancet. However, complementary approaches are essential to improve diet quality.
Health risks associated with deficiency
Insufficient levels of micronutrients are associated with blindness, intellectual disability, reduced productivity, poor growth, and death. Deficiencies in any of the four micronutrients (iron, zinc, folate, and vitamin A) affect approximately 372 million children under the age of 5 and 1.2 billion non-pregnant women of reproductive age. Many other micronutrients slip through the cracks due to missing measurements.
This led to dietary intake data being used as a proxy. Existing literature and modeling analyzes indicate that intakes of iodine, vitamin E, calcium, iron, some B vitamins, and vitamin C are insufficient for 4 to 5 billion people. Some micronutrients, such as iodine, are routinely added to salt and other staple foods, so these may be overestimated.
Large-scale food fortification (LSFF)
Large-scale food fortification (LSFF) is a public health strategy to reduce the prevalence of micronutrient deficiencies. Current estimates put the number of countries doing this at more than 150. Fortified foods range from salt and cooking oil to flour and grains. These programs currently prevent 87% of iodine deficiencies, and salt iodization is the cheapest at 1 cent per person.
These appear to be promising and cost-effective approaches if properly designed and implemented. However, global impacts across all population groups are not well quantified, as most studies have focused on women and preschool children, and impacts can vary significantly between countries depending on diet and program implementation.
In this study, the authors say they aim to understand the impact and associated costs of these programs on a global scale, and are the first of their kind. They used data from the Global Fortification Data Exchange to input fortification standards, compliance, and coverage, and to adjust previous impact estimates. The model focused on 13 micronutrients, tailored to the LSFF program, and used modeled dietary intake distributions to estimate inadequate intakes across 185 countries.
Nutritional fortification reduces micronutrient deficiencies
The researchers found that compared to no fortification, current programs could prevent 7 billion people per year from nutrient deficiencies (the sum of the number of people with inadequate intakes of each of the 13 micronutrients). All five fortified foods cost just over $1 billion each year, or an average of 18 cents per person.
It is estimated that iodine fortification has eliminated intake deficiencies for 3.3 billion people, and iron fortification has eliminated intake deficiencies for 1.4 billion people. Despite these programmes, 38.6 billion inadequate intakes remain uncorrected, highlighting significant gaps in diet quality and program coverage.
Improved compliance nearly doubles global enforcement impact
Improving program compliance to at least 90% would nearly double the effectiveness and prevent 13.1 billion people from inappropriate intake. The cost would be 23 cents per person, totaling $3.48 billion annually. Vitamin A will be the biggest increaser in intake, potentially preventing 1.1 billion people worldwide from becoming deficient.
Aligning standards provides benefits, but falls short of compliance.
If the fortification standards were met in addition to improved compliance, more than 4 billion additional cases of inappropriate consumption would be prevented, for an estimated total of 17.2 billion, at an annual cost of $6.56 billion (63 cents per person), although the impact would be smaller because many countries have already fortified beyond recommended levels.
Compliance, enforcement, and coverage
In addition to the above measures, comprehensively expanding the scope of enforcement could prevent 24.7 billion cases of inappropriate ingestion. The cost would be $9.19 billion annually, or $1.15 per person.
Most of this is used for flour fortification, with rice flour accounting for less than 25% and other foods accounting for 1-8% each. To scale these programs in the most cost-effective manner, they must be targeted. Countries with limited coverage and where some industrially produced staple foods are widely consumed. Benefits vary widely depending on national dietary patterns and infrastructure.
Risk of overdose
Researchers also emphasized the need to adhere to World Health Organization (WHO) guidelines and establish surveillance systems. These will help ensure that such programs are based on each country’s needs and do not pose an unacceptable risk of overdose. This mainly applies to iodine, selenium and zinc.
The modeled changes could put more than 15% of the world’s population at risk of excessive iodine and zinc intake, but this risk is unevenly distributed across countries and varies by reference intake level and program design. However, there were large differences between countries in both prevention rates and overdose risks.
Vulnerable groups require additional targeted nutritional interventions
Even with all these enhancements, there would still be 20.9 billion cases of inappropriate intake left uncorrected. This indicates the need for other approaches to supplement food fortification, such as improving average diet quality and availability.
This should include diverse and nutritious foods in home country contexts, which remain economically unaffordable for 2.6 billion people. Additional interventions may be required to meet the increasing needs of young children and pregnant and lactating women.
Restrictions
Although this model provides some useful estimates of the reach and cost of LSFF, it has important limitations. It relies on the Global Dietary Database, which assumes a fixed calorie intake for each country, which can lead to inaccuracies. We also use national food balance data from the Food and Agriculture Organization, which does not take into account food waste or small-scale production. Compliance is estimated using proxies that can exaggerate the impact of the program, and missing data are filled using proxies that can similarly introduce bias.
Additionally, the analysis excludes biofortification and supplementation programs, despite their role in providing multiple micronutrients. Cost estimates are based on fixed premix pricing, which can be reduced by up to 48% for large-scale deployments. Finally, deterministic modeling techniques do not incorporate uncertainty in the estimates.
Fortification should be combined with dietary diversity and supplements
LSFF is a cost-effective and scalable intervention that can help billions of people who cannot afford or do not have access to high-quality meals. This study evaluates three steps that can close existing gaps in programs while ensuring safety.
Objective micronutrient measurements are required to verify that these modeled estimates accurately reflect actual deficiencies. Additionally, future research should strengthen global databases by including missing programs such as biofortification and improving data collection in countries most in need.
However, researchers emphasize the need for comprehensive policies to close this gap. “Long-term success will depend on parallel investments in dietary diversity, supplements and robust monitoring systems to ensure fair and safe access to essential micronutrients.”
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