title: Provitamin A-biofortified maize increases serum β-carotene, but not retinol, in marginally nourished children: a cluster-randomized trial in rural Zambia.
abstract: BACKGROUND
  Vitamin A deficiency remains a nutritional concern in sub-Saharan Africa. Conventionally bred maize hybrids with high provitamin A carotenoid concentrations may have the potential to improve vitamin A status in maize-consuming populations.
  
  
  OBJECTIVE
  We evaluated the efficacy of regular provitamin A carotenoid-biofortified "orange" maizemeal (∼15 μg β-carotene/g) consumption in improving vitamin A status and reducing vitamin A deficiency in children.
  
  
  METHODS
  This was a cluster-randomized controlled trial in the rural farming district of Mkushi, Zambia. All 4- to 8-y-old children in an ∼400-km(2) area were identified and grouped by proximity into clusters of ∼15-25 children. We randomly assigned clusters to 1) orange maizemeal (n = 25), 2) white maizemeal (n = 25), or 3) a parallel, nonintervention group (n = 14). Children in intervention clusters (n = 1024) received 200 g maizemeal for 6 d/wk over 6 mo; the maizemeal was prepared according to standardized recipes and served in cluster-level kitchens. Staff recorded attendance and leftovers. We collected venous blood before and after the intervention to measure serum retinol, β-carotene, C-reactive protein, and α1-acid glycoprotein.
  
  
  RESULTS
  Intervention groups were comparable at baseline, and vitamin A status was better than anticipated (12.1% deficient on the basis of serum retinol <0.7 μmol/L). Although attendance at meals did not differ (85%), median daily maize intake was higher in white (154 g/d) than in orange (142 g/d) maizemeal clusters. At follow-up, mean serum β-carotene was 0.14 μmol/L (95% CI: 0.09, 0.20 μmol/L) higher in orange maizemeal clusters (P < 0.001), but mean serum retinol (1.00 ± 0.33 μmol/L overall) and deficiency prevalence (17.1% overall) did not differ between arms.
  
  
  CONCLUSIONS
  In this marginally nourished population, regular biofortified maizemeal consumption increased serum β-carotene concentrations but did not improve serum retinol. This trial was registered at clinicaltrials.gov as NCT01695148.
authors.affiliation: Center for Human Nutrition, Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD; apalme17@jhu.edu.
authors.forename: Amanda C
authors.identifier: http://orcid.org/0000-0002-3212-955X
authors.initials: AC
authors.lastname: Palmer
authors.affiliation: National Food and Nutrition Commission;
authors.forename: Ward
authors.initials: W
authors.lastname: Siamusantu
authors.affiliation: Tropical Diseases Research Centre; and.
authors.forename: Justin
authors.initials: J
authors.lastname: Chileshe
authors.affiliation: Center for Human Nutrition, Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD;
authors.forename: Kerry J
authors.initials: KJ
authors.lastname: Schulze
authors.affiliation: Center for Human Nutrition, Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD;
authors.forename: Maxwell
authors.initials: M
authors.lastname: Barffour
authors.affiliation: Craft Technologies Inc.
authors.forename: Neal E
authors.initials: NE
authors.lastname: Craft
authors.affiliation: Center for Human Nutrition, Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD;
authors.forename: Ngosa
authors.initials: N
authors.lastname: Molobeka
authors.affiliation: Tropical Diseases Research Centre; and.
authors.forename: Ng'andwe
authors.initials: N
authors.lastname: Kalungwana
authors.affiliation: Center for Human Nutrition, Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD;
authors.forename: Margia A
authors.initials: MA
authors.lastname: Arguello
authors.affiliation: Center for Human Nutrition, Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD;
authors.forename: Maithilee
authors.initials: M
authors.lastname: Mitra
authors.affiliation: Center for Human Nutrition, Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD;
authors.forename: Bess
authors.initials: B
authors.lastname: Caswell
authors.affiliation: Center for Human Nutrition, Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD;
authors.forename: Rolf Dw
authors.initials: RD
authors.lastname: Klemm
authors.affiliation: Center for Human Nutrition, Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD;
authors.forename: Keith P
authors.identifier: http://orcid.org/0000-0001-9458-362X
authors.initials: KP
authors.lastname: West
mesh_terms: D002097:C-Reactive Protein / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D004032:Diet; D002523:Edible Grain; D005260:Female; D005527:Food, Fortified; D006801:Humans; D008297:Male; D009752:Nutritional Status; D000072664:Provitamins / Q000097:blood / Q000494:pharmacology* / Q000627:therapeutic use; D012424:Rural Population; D016896:Treatment Outcome; D014801:Vitamin A / Q000097:blood*; D014802:Vitamin A Deficiency / Q000097:blood / Q000178:diet therapy / Q000188:drug therapy; D015024:Zambia; D003313:Zea mays; D019207:beta Carotene / Q000097:blood / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D000072664:Provitamins; D019207:beta Carotene; D014801:Vitamin A; D002097:C-Reactive Protein
keywords: Zambia; beta-carotene; biofortification; deficiency; provitamin A; serum retinol; vitamin A