Identification and production of local carotene-rich foods to combat vitamin A malnutrition.

OBJECTIVES: To address, with respect to improvement of human vitamin A status by dietary approaches, the three theoretical postulates that: 1) the most practical and economical manner to increase the amount of dietary vitamin A available to low-income persons in low-income nations is through plant sources of provitamin A carotenoids; 2) there will be constraints and limitation to the efficiency of a given intervention approach related to behavioural, cultural, biological and botanical considerations; and 3) the nature of these constraints and limitations must be understood, and then overcome where possible, to maximize the impact of such interventions on the vitamin A status of developing country populations. CONCLUSIONS: We review how local plant sources of provitamin A that would be acceptable for the at-risk populations and outline six settings and scenarios for the processing of carotene-rich foods: 1) cooking for hygiene; 2) long-term preservation; 3) compacting to reduce volume; 4) formulation for specific consumers; 5) improving bioavailability and bioconversion; and 6) to increase 'value added' in commerce. We describe our experiences in Guatemala (with sweet potato flakes), and those of others in the Caribbean, the African Sahel, and East Africa (with solar-drying for preservation of a variety of plants), and in Sri Lanka (with leaf concentrates) in promoting increased carotene-rich food intake, and the lessons learned from their evaluations. This overall approach to combatting endemic hypovitaminosis A in developing countries is evaluated within the constraints of: 1) the volumes of plant-based foods required to satisfy vitamin A requirements; and 2) the controversy over the true bioconversion efficiency of provitamin A from plant sources into the biologically-available active vitamin.