Biofortified Orange-Fleshed Sweetpotato Can Meaningfully Reduce the Burden of Vitamin A Deficiency

Objectives: Inadequate vitamin A (VA) production and apparent intake are prevalent in Africa and South Asia where the disease burden of vitamin A deficiency (VAD) is concentrated. This study focused on estimating the potential impact of vitamin A-biofortified orange-fleshed sweetpotato (OFSP) on reducing the burden of VAD. Methods: Country-specific VAD-related disability-adjusted life years (DALYs) from the Institute of Health Metrics and Evaluation’s (IHME) Global Health Data Exchange (GHDx) for 1990-2019 were merged with data from the Nutrient Balance Sheets (NBS). The maximum additional amount of VA that can be supplied by the OFSP intervention was calculated and the corresponding effectiveness (E) in each country was estimated and interpreted as the maximum potential percentage reduction in DALYs. The maximum annual reductions for VAD-related disease burden were then determined as well as the total DALYs saved under various scaling scenarios. Results: Interventions scaling OFSP collectively had the potential to save up to 41% of DALYs in Sub-Saharan Africa (SSA), 23% of DALYs in Latin America and the Caribbean (LAC) and 22% of DALYs in East Asia and the Pacific (EAP) as of 2019 at maximum scale. Ethiopia, Niger, Chad, Nigeria, and Madagascar had the potential to save the most DALYs in absolute terms (greater than 50,000 DALYs). Holding the annual number of DALYs lost constant, scaling scenarios of 25% and 75% (and faster rate) indicate that SSA can save between 4.0% and 16.6% of DALYs over a 30-year period; LAC can save between 2.4% and 10.4% of DALYs; and EAP can save between 2.2% and 8.9% of DALYs. Carrying the 2015-2019 trend in DALYs lost forward resulted in similar ranges of percentages of DALYs saved though much lower in absolute terms. Under all scenarios SSA would save the greatest number of VAD-related DALYs. Conclusions: Investments in OFSP development and delivery have the potential to further reduce the burden of VAD, particularly in SSA. While significant scaling efforts are required to achieve the impacts shown here, strategies which incorporate economies of scale, such as mainstreamed breeding approaches to include vitamin A in all improved varieties, could cost-effectively achieve such levels while also addressing other food system-related goals.