title: Plasma concentration response to drinks containing beta-carotene as carrot juice or formulated as a water dispersible powder.
abstract: BACKGROUND
  Bioavailability of beta-carotene is highly variable and depends on the source, the formulation and other nutritional factors.
  
  
  OBJECTIVE
  It was the aim of the study to compare beta-carotene plasma response to b-carotene dosing with two commercially available drinks, containing beta-carotene from carrot juice or as water dispersible beta-carotene powder. Design In a randomized, parallel group study design, 4 volunteers per group received daily beta-carotene doses of 6-7 or 18-22 mg of either drink over 6 weeks. Blood samples for determination of carotenoid and vitamin A plasma concentrations were collected before supplementation and over the dosing period.
  
  
  RESULTS
  Apparent steady-state beta-carotene concentrations were attained after 40 days of supplementation. Consumption of the beverage containing beta-carotene as a water dispersible powder resulted in a higher response of beta-carotene plasma concentrations with increments of 3.84 +/- 0.60 micromol/L (p < 0.05, dose: 7.2 mg/d) and 5.04 +/- 0.72 micromol/L (p < 0.05, dose: 21.6 mg/d), respectively, in comparison to the carrot juice-based drink with increments of 0.42 +/- 0.33 micromol/L (dose: 6 mg/d) and 1.71 +/- 0.55 micromol/L (dose: 18 mg/d), respectively. beta-carotene was cleared from the plasma with an apparent half-life of 6-11 days. Plasma concentrations of alpha-carotene, beta-cryptoxanthin, lutein, zeaxanthin, and lycopene remained almost unchanged, whereas retinol plasma concentrations increased slightly. By contrast, with the exception of elevated 13-cis-retinoic acid in one group (21.6 mg/d, water dispersible powder), the concentrations of all-trans-retinoic acid, and the oxo-derivatives or retinoic acid were not significantly affected by b-carotene supplementation.
  
  
  CONCLUSIONS
  The results confirm that the relative bioavailability of beta-carotene depends largely on the source of b-carotene and demonstrate the superior bioavailability of beta-carotene powder in comparison to that in carrot juice.
authors.affiliation: Philipp Klee-Institute of Clinical Pharmacology, Hospital Wuppertal GmbH, Heusnerstr. 40, Germany. petra.thuermann@klinikum-wuppertal.de
authors.forename: Petra A
authors.initials: PA
authors.lastname: Thürmann
authors.forename: Joachim
authors.initials: J
authors.lastname: Steffen
authors.forename: Christoph
authors.initials: C
authors.lastname: Zwernemann
authors.forename: Claude-Pierre
authors.initials: CP
authors.lastname: Aebischer
authors.forename: Willy
authors.initials: W
authors.lastname: Cohn
authors.forename: Gernot
authors.initials: G
authors.lastname: Wendt
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schalch
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000008:administration & dosage / Q000493:pharmacokinetics*; D001628:Beverages; D001682:Biological Availability; D018552:Daucus carota / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D006207:Half-Life; D006801:Humans; D007408:Intestinal Absorption; D008297:Male; D008657:Metabolic Clearance Rate; D011208:Powders; D024505:Tocopherols / Q000097:blood; D014801:Vitamin A / Q000097:blood*; D019207:beta Carotene / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*
chemical_list: D000975:Antioxidants; D011208:Powders; D019207:beta Carotene; D014801:Vitamin A; D024505:Tocopherols