title: Beta-carotene-rich orange-fleshed sweet potato improves the vitamin A status of primary school children assessed with the modified-relative-dose-response test.
abstract: BACKGROUND
  Beta-carotene-rich orange-fleshed sweet potato (OFSP) is an excellent source of provitamin A. In many developing countries, sweet potato is a secondary staple food and may play a role in controlling vitamin A deficiency.
  
  
  OBJECTIVE
  The objective was to determine the efficacy of daily consumption of boiled and mashed OFSP in improving the vitamin A status of primary school children.
  
  
  METHODS
  Children aged 5-10 y were randomly assigned to 2 groups. The treatment group (n = 90) consumed 125 g boiled and mashed OFSP (1031 retinol activity equivalents/d as beta-carotene), and the control group (n = 90) consumed an equal amount of white-fleshed sweet potato devoid of beta-carotene for 53 school days. All children were dewormed to exclude helminthic infection. The modified-relative-dose-response test for vitamin A status was conducted before and after intervention.
  
  
  RESULTS
  The estimated intervention effect for the ratio of 3,4-didehydroretinol to retinol (DR:R) was -0.008 (95% CI: -0.015, -0.001; P = 0.0203), which indicated a greater improvement in vitamin A liver stores in the treatment group than in the control group. The proportions of children with normal vitamin A status (DR:R < 0.060) in the treatment group tended to increase from 78% to 87% (P = 0.096) and did not change significantly (from 86% to 82%) in the control group (P = 0.267). These proportions were not used to test the intervention effect or within-group changes because the study was powered to test the intervention effect on DR:R.
  
  
  CONCLUSIONS
  Consumption of OFSP improves vitamin A status and can play a significant role in developing countries as a viable long-term food-based strategy for controlling vitamin A deficiency in children.
authors.affiliation: Nutritional Intervention Research Unit, Medical Research Council, Parow, South Africa. paul.van.jaarsveld@mrc.ac.za
authors.forename: Paul J
authors.initials: PJ
authors.lastname: van Jaarsveld
authors.forename: Mieke
authors.initials: M
authors.lastname: Faber
authors.forename: Sherry A
authors.initials: SA
authors.lastname: Tanumihardjo
authors.forename: Penelope
authors.initials: P
authors.lastname: Nestel
authors.forename: Carl J
authors.initials: CJ
authors.lastname: Lombard
authors.forename: Ambrose J Spinnler
authors.initials: AJ
authors.lastname: Benadé
mesh_terms: D000886:Anthropometry; D000975:Antioxidants / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D027723:Ipomoea batatas; D008297:Male; D008517:Phytotherapy; D028321:Plant Preparations / Q000627:therapeutic use*; D012424:Rural Population; D014802:Vitamin A Deficiency / Q000097:blood / Q000188:drug therapy*; D019207:beta Carotene / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D000975:Antioxidants; D028321:Plant Preparations; D019207:beta Carotene