title: Bioefficacy of beta-carotene dissolved in oil studied in children in Indonesia.
abstract: BACKGROUND
  More information on the bioefficacy of carotenoids in foods ingested by humans is needed.
  
  
  OBJECTIVE
  We aimed to measure the time required for isotopic enrichment of beta-carotene and retinol in serum to reach a plateau, the extent of conversion of beta-carotene dissolved in oil with use of beta-carotene and retinol specifically labeled with 10 (13)C atoms, and the intraindividual variation in response.
  
  
  METHODS
  Indonesian children aged 8--11 y (n = 35) consumed 2 capsules/d, 7 d/wk, for < or =10 wk. Each capsule contained 80 microg [12,13,14,15,20,12',13',14',15',20'-(13)C(10)]beta-carotene and 80 microg [8,9,10,11,12,13,14,15,19,20-(13)C(10)]retinyl palmitate. Three blood samples were drawn per child over a period of < or =10 wk. HPLC coupled with atmospheric pressure chemical ionization liquid chromatography-mass spectrometry was used to measure the isotopic enrichment in serum of retinol with [(13)C(5)]retinol and [(13)C(10)]retinol and of beta-carotene with [(13)C(10)]beta-carotene. The beta-carotene in the capsules used had a cis-trans ratio of 3:1.
  
  
  RESULTS
  Plateau isotopic enrichment was reached by day 21. The amount of beta-carotene in oil required to form 1 microg retinol was 2.4 microg (95% CI: 2.1, 2.7). The amount of all-trans-beta-carotene required to form 1 microg retinol may be lower.
  
  
  CONCLUSIONS
  The efficiency of conversion of this beta-carotene in oil was 27% better than that estimated previously (1.0 microg retinol from 3.3 microg beta-carotene with an unknown cis-trans ratio). The method described can be extended to measure the bioefficacy of carotenoids in foods with high precision, requiring fewer subjects than other methods.
authors.affiliation: Division of Human Nutrition and Epidemiology, Wageningen University, Wageningen, Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: van Lieshout
authors.forename: C E
authors.initials: CE
authors.lastname: West
authors.lastname: Muhilal
authors.forename: D
authors.initials: D
authors.lastname: Permaesih
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.forename: X
authors.initials: X
authors.lastname: Xu
authors.forename: R B
authors.initials: RB
authors.lastname: van Breemen
authors.forename: A F
authors.initials: AF
authors.lastname: Creemers
authors.forename: M A
authors.initials: MA
authors.lastname: Verhoeven
authors.forename: J
authors.initials: J
authors.lastname: Lugtenburg
mesh_terms: D001711:Biotransformation; D002214:Capsules; D002247:Carbon Isotopes; D002626:Chemistry, Pharmaceutical; D002648:Child; D002853:Chromatography, Liquid; D004224:Diterpenes; D005243:Feces / Q000737:chemistry; D005260:Female; D006801:Humans; D007214:Indonesia; D008297:Male; D013058:Mass Spectrometry; D000084562:Retinyl Esters; D012424:Rural Population; D014801:Vitamin A / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics*; D019207:beta Carotene / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*
chemical_list: D002214:Capsules; D002247:Carbon Isotopes; D004224:Diterpenes; D000084562:Retinyl Esters; D019207:beta Carotene; D014801:Vitamin A; C014794:retinol palmitate