2011 Annual Report 1a.Objectives (from AD-416) Biofortification of staple food crops is a promising strategy for increasing dietary Vitamin A intake and improving Vitamin A status in populations at risk of deficiency. The purpose of this study is to determine the Vitamin A equivalence of carotenoids in high-carotenoid varieties of cassava. 1b.Approach (from AD-416) We plan to conduct a single site Phase II intervention study in healthy adult women. Women will serve as their own controls, and will be fed three treatments in random order: a single meal of white, non-biofortified low-carotenoid cassava with oil, a similar meal of bio-fortified cassava that is high in carotenoids without oil, and a similar meal of bio-fortified cassava with oil. Carotenoids and vitamin A will be measured in the triacylglycerol-rich lipoprotein (TRL) fraction of plasma by standard methods involving ultracentrifugation (to concentrate the TRL fraction) followed by reversed-phase HPLC using electrochemical detection. We plan to collect sufficient data to identify the times of the first appearance and peak concentrations of retinol, retinyl esters, alpha-carotene (AC), beta-carotene (BC), beta-carotene isomers (BCI) and cryptoxanthin (CX) in TRL when a single meal containing moderately high amounts of carotenoids from bio-fortified cassava is fed to healthy adult women. We will use these data to determine the vitamin A equivalency of bio-fortified cassava in adult women. 3.Progress Report In FY2011, procedures for the study were finalized, and workers trained in sample collection, high performance liquid chromatography, and ultracentrifugation techniques. The dietary intervention was tested for carotenoids and cyanogens (both in-house and independently), and approved. Subject recruitment has begun.