Biofortification Strategies for Grain Nutritional Enhancement

Biofortification encompasses a suite of interventions aimed at increasing the density and bioavailability of essential micronutrients—such as iron, zinc, provitamin A and calcium—in staple cereal grains before harvest. Three principal approaches have emerged: genetic biofortification, which exploits natural variation and modern breeding techniques to incorporate high-nutrient traits into elite cultivars; agronomic biofortification, which uses optimised fertiliser regimens including soil and foliar applications of micronutrients; and transgenic or genome-editing strategies that enhance nutrient uptake, transport and sequestration pathways. Synergies between these methods are increasingly pursued, for example combining zinc-efficient genotypes with targeted foliar sprays to overcome limitations of phloem mobility and soil deficiencies. Advances in high-throughput phenotyping, molecular marker development and nanotechnology-based delivery systems have accelerated progress and offered new avenues to tailor interventions to local environments. The global significance of biofortification lies in its potential to deliver sustainable, cost-effective nutritional gains to smallholder farming communities, reduce reliance on external fortification or supplementation programmes and address persistent micronutrient deficiencies in low-resource settings. Practical applications extend from integrating micronutrient-enriched cultivars into national breeding pipelines to developing extension packages that combine fertiliser recommendations with seed deployment and post-harvest handling guidelines to retain nutrient integrity through processing and storage.

Research from Nature Portfolio

Studies mapping the micronutrient composition of staple cereals at subnational scales have revealed substantial geospatial variation driven by soil pH, organic matter content, rainfall and topography. In two major cereal-producing regions, concentrations of zinc, iron, calcium and selenium in locally grown grains varied widely, influencing dietary intakes and biomarker status among rural households consuming home-grown cereals. These findings underscore the importance of tailoring biofortification interventions to environmental gradients and prioritising regions where natural soil fertility constraints limit the effectiveness of breeding or fertiliser strategies alone. Earlier global assessments of dietary calcium and zinc supply have documented a decline in population-level deficiency risks over recent decades, yet more than one billion people remain at risk, particularly in sub-Saharan Africa and South Asia. Although average dietary supplies have improved, high variability persists between regions, signalling a need for integrated approaches that combine genetic cultivar improvements with soil and foliar nutrient management to achieve equitable micronutrient access.

Biofortification Strategies for Grain Nutritional Enhancement publication trend

The graph below shows the total number of articles in biofortification strategies for grain nutritional enhancement across all publications each year (not limited to Nature Index journals).

Technical terms

Biofortification: Enhancement of crop micronutrient density through genetic, agronomic or biotechnological methods before harvest.

Genetic biofortification: Use of conventional breeding or marker-assisted selection to incorporate high-nutrient traits into new crop varieties.

Agronomic biofortification: Application of mineral fertilisers—either to soil or foliage—to increase nutrient uptake and grain deposition.

Phloem mobility: Capacity of a nutrient ion to be transported through the plant’s phloem network and ultimately deposited in seeds or grains.

Quantitative trait locus (QTL): A genomic region associated with variation in a quantitative trait, such as grain zinc concentration.

References

1. Biofortified Crops Generated by Breeding, Agronomy, and Transgenic Approaches Are Improving Lives of Millions of People around the World. Frontiers in Nutrition (2018).
2. Agronomic biofortification of cereals with zinc: a review. European Journal of Soil Science (2017).
3. Advances in breeding for high grain Zinc in Rice. Rice (2016).
4. The nutritional quality of cereals varies geospatially in Ethiopia and Malawi. Nature (2021).
5. Dietary calcium and zinc deficiency risks are decreasing but remain prevalent. Scientific Reports (2015).
6. Improving nutrition through biofortification: A review of evidence from HarvestPlus, 2003 through 2016. Global Food Security (2017).