Efficacy of beta-carotene rich sweet potato to improve vitamin a status of Bangladeshi women - Preliminary results

Vitamin A deficiency is the leading cause of preventable blindness in children, which also increases the risk of disease and death from severe infections. Orange-fleshed sweet potato (OFSP) is a good source of pro-vitamin A and has been successfully tried in African countries as an effective means to ensure adequate intake of pro-vitamin A by mothers and children. We have conducted a randomized controlled trial in an urban poor community of Bangladesh to examine the efficacy of two different preparations of OFSP in women with marginal vitamin A deficiency. The subjects (n=120) were aged between 18-35 years with serum retinol <1.05 μmol/L and hemoglobin >90 g/L and CRP <5 mg/L. They were dewormed with 400 mg albendazole and then 10 mg of deuterated retinol ([²H₄]-retinyl acetate) was given orally to determine total body vitamin A pool size. The subjects were randomly assigned to one of the following four treatment groups to receive 6 d/wk for 60 days: (1) boiled white-fleshed sweet potatoes (WFSP); (2) 600 μg RAE as boiled OFSP; (3) 600 μg RAE as fried OFSP; or (4) 600 μg RAE as a retinyl palmitate capsule, and boiled WFSP. Night vision of the subjects was assessed, as a proxy for vitamin A status, before and after intervention by performing 'dark adaptation test'. Blood samples collected before and after intervention were light-protected and stored on ice until plasma was separated, and then stored at - 20C until shipment to University of California Davis under frozen condition. The samples will be analyzed in UC Davis for plasma isotopic ratios using GC-MS following the isolation of retinol from plasma with HPLC, to determine vitamin A pool size before and after supplementation. The preliminary results from partial analysis of the available data will be presented. (author)