The research and implementation continuum of biofortified sweet potato and maize in Africa

Abstract

The enhancement of sweet potato and maize with provitamin A carotenoids has been part of HarvestPlus's research continuum since the formation of the biofortification project. This review includes case studies of biofortification strategies used for sweet potato in Uganda and orange maize in Zambia. The current status of the science and release of biofortified varieties was reviewed by three scientists who were part of the HarvestPlus program for more than a decade with input from a scientist who experienced orange maize dissemination in Zambia. High ␤-carotene varieties of sweet potato were introduced into South Africa and Mozambique, and efficacy and effectiveness studies, respectively, showed promise to improve vitamin A status, followed by dissemination efforts in Uganda. A randomized, controlled effectiveness trial tested extension models to promote sweet potato and assessed vitamin A intake among Ugandans. Orange maize breeding was initially a challenge, but considering that the carotenoid biosynthetic pathway was present in maize germplasm, breeders quickly bred higher amounts of provitamin A into the maize that was ultimately released in Zambia. Initial resistance occurred because orange maize was associated with yellow maize, which had negative connotations associated with food aid and animal feed, and consumers preferred white maize. Currently, both orange crops are available on the market.

Vitamin A Supplementation Programs and Country-Level Evidence of Vitamin A Deficiency

“…Biofortified staple crops are relatively new in the scheme of nutritional interventions. In Zambia by 2015, seeds of one biofortified maize variety had gained only 1% of the market [107]. Lastly, our analysis did not include fortified blended flours (e.g., corn–soy blend plus), lipid-based nutrient supplements, or fortified complementary food products (e.g., porridges).…”

Staple crops biofortified with increased vitamins and minerals: considerations for a public health strategy

“…The involvement of min-istries of health, stakeholders, and local researchers and the dissemination of research findings have also been effective in facilitating adoption. 19,22,41…”

Overlapping vitamin A interventions in the United States, Guatemala, Zambia, and South Africa: case studies

“…High‐dose VAS is administered to children <5 years every 6 months with high coverage rates (Table ) and to postpartum women within 8 weeks of delivery. The country has mandated sugar fortification with retinyl palmitate for all human consumption at the household level and has scaled‐up the release of biofortified orange maize and orange‐fleshed sweet potato . Furthermore, the consumption of varied foods rich in VA, such as red palm oil, is being promoted through the Ministry of Agriculture.…”

“…The country has mandated sugar fortification with retinyl palmitate for all human consumption at the household level 39,40 and has scaled-up the release of biofortified orange maize and orange-fleshed sweet potato. 41 Furthermore, the consumption of varied foods rich in VA, such as red palm oil, is being promoted through the Ministry of Agriculture. This is in addition to having diets high in vegetablesourced provitamin A carotenoids in some cohorts, which have been quantified with dietary recalls in children.…”