Publications /  Annual Report 1998

"Because it is difficult to get supplements to some of the world’s poorest or strife-ridden countries, many assistance agencies are now seeking to fortify local foods with vitamin A."

Vitamin A–rich sweetpotatoes are being introduced in Kenya to help ward off crippling diseases, especially in young children.

An estimated 250 million children in developing countries are vitamin A-deficient, putting them at risk not only for night blindness but also for the highly infectious diseases enabled by reductions in their immune function.

Since the discovery of vitamin A’s impact on children’s health in the 1970s, aid groups have donated and helped distribute vitamin A capsules to malnourished children and lactating women. But because it is difficult to get supplements to some of the world’s poorest or strife-ridden countries, many assistance agencies are now seeking to fortify local foods with vitamin A.

In a study in Kenya, new varieties of sweetpotatoes (Ipomoea batatas) that are rich in beta-carotene, a precursor of vitamin A, have been introduced and promoted to women farmers. These varieties have been selected by CIP and Kenyan scientists to help alleviate vitamin A deficiencies, especially among the young.

The Kenyan study was one of five two-year intervention programs undertaken by the International Center for Research on Women (ICRW) to explore ways to strengthen women’s contributions to reducing iron and vitamin A deficiencies. Other studies were carried out in Ethiopia, Peru, Tanzania, and Thailand. The Kenyan study was a collaborative effort by the National Potato Research Center of the Kenyan Agricultural Research Institute (KARI), CIP, the NGO CARE’s program in Homa Bay District, and farmers.

Sweetpotatoes are a widely cultivated traditional crop in Kenya. The major sweetpotato-producing region is the western part of the country, where vitamin A deficiency is common. In Kenya, at present, the sweetpotatoes most commonly grown are white-fleshed varieties low in beta-carotene. In western Kenya, sweetpotatoes are eaten as a supplementary staple food and are consumed whole (boiled) or are mashed and eaten with legumes, leafy vegetables, meat, or fish. Sweetpotatoes are considered a woman’s crop, as they can be grown on the small plots of land women receive from their husbands at marriage.

In the study, orange-fleshed sweetpotatoes rich in vitamin A were introduced to 20 women’s group in two districts of western Kenya where vitamin A deficiency was high and where white sweetpotatoes were a common secondary staple (the primary food is maize). Half of the women’s groups received a package designed to promote the use and consumption of orange sweetpotatoes, including nutrition education and training in food processing, packaging, preparation and marketing.

Results indicate that orange-fleshed sweetpotatoes and sweetpotato-based food products were acceptable to both producers and consumers and helped increase vitamin A intake. Several of the new sweetpotato varieties grown in the on-farm trials performed well with respect to yield and pest resistance and also were high in beta-carotene.

Consumer preferences are a crucial factor in variety evaluation and selection.

The appearance, taste, and texture of the new varieties were well accepted by community groups. Processed food products made by substituting sweetpotato for other ingredients were also popular. And growing conditions in the study proved favorable for growing several crops of sweetpotato per year. All of this factors could make sweetpotato an affordable beta-carotene–rich food, attainable year-round.

Widespread distribution of the orange-fleshed sweetpotato vines occurred as soon as the study project was under way. Given this popularity, the use of orange sweetpotatoes should grow, as KARI offices plan to continue to make planting materials available to farmers. Western Kenyan farmers’ tradition of passing vine cuttings to other farmers free of charge should also help assure continued rapid diffusion. On-farm trial data showed the new orange varieties survived drought well and had higher yields than the traditional white varieties, both important factors for their sustained cultivation.

Researchers noted that simply distributing beta-carotene–rich varieties of sweetpotatoes and providing minimal support for their production did not automatically enhance the nutritional status of young children. Promotional activities educating women in the use and consumption of orange sweetpotato were critical in increasing the vitamin A intake of young children.

The intervention strengthened women’s control over some of the resources they need to feed their families and improve the nutritional status of family members, especially young children. One of the key lessons learned was that orange-fleshed sweetpotato varieties are adopted most when introduced within the context of extension and education on family health and nutrition. Mothers must be convinced that these new varieties are good for their children. In a foreword to one of his reports, Dr. Cyrus Ndiritu, director of KARI, affirmed these benefits, writing: "Study results indicate that orange-fleshed sweetpotato (including leaves) and sweetpotato-based food products are highly nutritious and can significantly contribute to year-round alleviation of vitamin A deficiency among children under five years of age."