Global · October 2024 — The scientific consensus on biofortification — the process of increasing the micronutrient density of staple crops through conventional breeding, agronomic practices, or transgenic approaches — has solidified over the past two decades. By 2024, the evidence base had matured to the point where the question was no longer whether biofortified crops can improve nutritional status, but how to scale their adoption to reach the billions of people affected by "hidden hunger": the chronic deficiency of essential vitamins and minerals that stunts growth, weakens immune function, and impairs cognitive development even when caloric intake is sufficient.
According to data from HarvestPlus and the CGIAR research network, nearly 450 biofortified crop varieties of 12 different staple crops had been officially released across 41 countries by 2024. These include iron-biofortified beans, pearl millet, and rice; zinc-biofortified wheat, rice, and maize; and provitamin A-biofortified cassava, maize, and orange-fleshed sweet potato.
The Hidden Hunger Problem
Micronutrient deficiencies affect an estimated 2 billion people globally, with the heaviest burden falling on women and children in low- and middle-income countries (LMICs). Iron deficiency is the most common, affecting approximately 40 per cent of children under five and 30 per cent of women of reproductive age in developing countries. Zinc deficiency contributes to stunted growth and increased susceptibility to infectious diseases. Vitamin A deficiency remains a leading cause of preventable childhood blindness and increases the risk of death from common childhood infections.
Traditional interventions — supplementation programmes, food fortification, and dietary diversification — have achieved significant successes but face persistent limitations. Supplementation requires continuous supply chains and compliance. Industrial food fortification reaches only those who purchase processed foods, missing rural subsistence households. Dietary diversification, while the ideal long-term solution, depends on income growth and market access that remain out of reach for the poorest.
Biofortification offers a complementary approach: it embeds improved nutrition within the seeds that farmers already plant and the foods that households already consume. Once a biofortified variety is developed and distributed, the nutritional benefit is self-sustaining — it does not require ongoing supply chains, repeated purchases, or behavioural change beyond the decision to plant the improved variety.
The Evidence Base: From Efficacy to Adoption
The established body of evidence confirms the efficacy of biofortified crops in improving nutritional status markers across multiple micronutrients:
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Iron: Regular consumption of iron-biofortified crops — including beans, pearl millet, and rice — has been shown to consistently improve iron status in vulnerable groups, including children and women of reproductive age. Randomised controlled trials in India, Rwanda, and the Philippines demonstrated measurable improvements in iron stores and reductions in iron deficiency anaemia among regular consumers.
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Vitamin A: Crops such as orange-fleshed sweet potato and provitamin A-enriched maize and cassava have demonstrated success in reducing vitamin A deficiency. Some studies have used functional markers — such as visual adaptation to low light — as evidence of improved vitamin A status, providing objective physiological confirmation beyond blood biomarkers.
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Zinc: Zinc-biofortified crops, particularly wheat and rice, are a primary focus for public health nutrition in South Asia, where zinc deficiency is widespread. These crops are being integrated into large-scale cultivation programmes in India, Pakistan, and Bangladesh.
2024 Research Frontiers
While the efficacy evidence is robust, research published through 2024–2026 has moved beyond proof-of-efficacy trials to focus on three critical frontiers: adoption barriers, scalability, and complex nutritional interactions.
Adoption Barriers: A Systematic Review
A notable 2024 systematic review published in Nutrition Research Reviews analysed the facilitators and barriers to the adoption of biofortified crops. The review synthesised evidence from multiple countries and found that farmers are more likely to adopt biofortified varieties when they are aware of their relative advantages — including both production benefits (such as disease resistance or drought tolerance) and nutritional outcomes compared to traditional varieties.
Key barriers identified included:
- Limited awareness among farmers and consumers about the nutritional benefits
- Insufficient seed multiplication and distribution systems
- Sensory differences (in some cases, biofortified varieties have different taste, texture, or cooking properties)
- Policy and regulatory gaps in some countries that do not distinguish biofortified varieties in seed certification systems
The Zinc-Iron Interaction Dilemma
A 2025 review highlighted a technical challenge that complicates multi-nutrient biofortification: the "zinc-iron interaction dilemma." Because zinc and iron can interact during plant growth — sometimes antagonistically — agronomic and breeding strategies must be carefully calibrated to ensure that enhancing one nutrient does not inadvertently deplete the other. This is particularly relevant for crops like wheat and rice, where both zinc and iron biofortification are public health priorities.
The research community is addressing this through advanced breeding techniques, including gene editing (CRISPR-Cas systems) and transgenic approaches that can handle multiple nutritional traits simultaneously. These technologies offer the potential to overcome limitations in genetic variability that constrain conventional breeding, though regulatory and public acceptance challenges remain.
Digital Tools and Data Dashboards
New digital tools featured in Nature Food in 2024 have been developed to track the impacts and reach of biofortified crops. These data dashboards make complex nutritional and agricultural data accessible to policymakers, allowing them to monitor adoption rates, estimate nutritional impact, and identify gaps in coverage. The tools integrate data from breeding programmes, seed distribution systems, household consumption surveys, and nutritional biomarker studies into a single platform.
Integration with School Feeding Programmes
Projects in several countries, including Tanzania, are actively testing the integration of biofortified foods into school meals. This approach leverages existing institutional procurement and feeding infrastructure to reach at-risk children at scale. School feeding programmes that source biofortified maize, beans, or sweet potatoes from local farmers create a dual benefit: improved nutrition for children and a guaranteed market for smallholder farmers growing biofortified varieties.
Agronomic Biofortification: Fertilisers as a Complementary Pathway
Beyond genetic biofortification, agronomic approaches — using specialised fertilisers to boost nutrient content in crops — gained attention in 2024. Zinc and selenium fertilisation, in particular, has been deployed at scale in countries such as Turkey (for zinc) and Finland (for selenium). Research on nanoparticle-based fertiliser applications showed promise for improving nutrient uptake efficiency, though the technology remains at an earlier stage of development.
Agronomic biofortification offers the advantage of speed: it can be deployed immediately on existing crop varieties without waiting for breeding cycles. However, it requires ongoing fertiliser application and supply chains, unlike genetic biofortification, which is self-sustaining once the seed is distributed.
Expanding the Evidence to High-Income Countries
A 2024 scoping review examined the potential of biofortification in high-income settings. While traditionally focused on LMICs to address severe deficiencies, researchers are now exploring whether biofortification can help address nutrient shortfalls in wealthier nations, where marginal deficiencies — particularly in iron, zinc, and vitamin D — persist despite generally adequate caloric intake. Evidence in these contexts remains limited, but the review identified potential applications in populations with restricted diets, older adults, and communities with limited access to diverse foods.
The Scaling Challenge
Despite the progress, the gap between the number of biofortified varieties released and the number of people actually consuming them remains substantial. The 109 million people reached represents a fraction of the 2 billion affected by hidden hunger. Closing this gap requires:
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Stronger seed systems: National seed multiplication and certification programmes must prioritise biofortified varieties, ensuring that farmers have reliable access to quality seed at affordable prices.
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Market creation: Consumer awareness campaigns, labelling standards, and institutional procurement (school feeding, food reserves, social protection programmes) can create demand pull that incentivises farmers to adopt biofortified varieties.
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Policy integration: Biofortification must be embedded in national agriculture, nutrition, and health policies — not treated as a standalone project but as a standard component of crop improvement and food security strategies.
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Sustained funding: Breeding, testing, and distribution of biofortified varieties require long-term investment. The CGIAR system, HarvestPlus, and national agricultural research systems depend on donor funding that has been under pressure in recent years.
Sources
- HarvestPlus. Biofortification Progress Report 2024. Washington, DC, 2024.
- CGIAR. "Biofortified Crops: Scaling Up." 2024.
- Nutrition Research Reviews. "Facilitators and Barriers to Adoption of Biofortified Crops: A Systematic Review." 2024.
- Nature Food. "Digital Dashboards for Tracking Biofortified Crop Impact." 2024.
- Cornell University / Alliance of Bioversity International and CIAT. Biofortification research publications. 2024.
- World Health Organization. "Micronutrient Deficiencies: Global Assessment." 2024.
- National Institutes of Health (NIH). "Zinc-Iron Interaction in Biofortified Crops." 2025.
- Farming First. "450 Biofortified Varieties Across 41 Countries." 2024.
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Institutional Research Desk · Foresight Institute of Research and Translation
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