title: Phytosterols can impair vitamin D intestinal absorption in vitro and in mice.
abstract: METHODS
  Adequate vitamin D status is necessary and beneficial for health, although deficiency and insufficiency are very common. As cholecalciferol (vitamin D(3) ) structure is close to cholesterol structure, we hypothesized that phytosterols, frequently used to decrease cholesterol, intestinal absorption and consequently to reduce hypercholesterolemia, may also interact with cholecalciferol absorption.
  
  
  RESULTS
  β-Sitosterol effect on cholecalciferol postprandial response was first assessed in mice. We then evaluated the effect of different sterols on (i) cholecalciferol micellar incorporation, (ii) cholecalciferol apical uptake and (iii) basolateral efflux in vitro or ex vivo. In mice, cholecalciferol bioavailability was 15-fold lower in the presence of β-sitosterol (p<0.05). This can partly be explained by the fact that phytosterols significantly impaired cholecalciferol incorporation into mixed micelles (from -16 to -36% depending on sterol micellar composition). This can also be due to the fact that in Caco-2 cells and mouse intestinal explants, phytosterols significantly lowered cholecalciferol apical uptake (from -13 to -39%). Conversely, phytosterols had no effect on cholecalciferol secretion at the basolateral side of Caco-2 cells.
  
  
  CONCLUSIONS
  The present data suggest for the first time that phytosterols can interact with vitamin D(3) intestinal absorption. This interaction can be explained by a competition for micellar incorporation and for apical uptake.
authors.affiliation: INRA, UMR 1260 Lipid Nutriments and Prevention of Metabolique Dieases, Marseille, France.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Goncalves
authors.forename: Béatrice
authors.initials: B
authors.lastname: Gleize
authors.forename: Romain
authors.initials: R
authors.lastname: Bott
authors.forename: Marion
authors.initials: M
authors.lastname: Nowicki
authors.forename: Marie-Josèphe
authors.initials: MJ
authors.lastname: Amiot
authors.forename: Denis
authors.initials: D
authors.lastname: Lairon
authors.forename: Patrick
authors.initials: P
authors.lastname: Borel
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Reboul
mesh_terms: D000818:Animals; D018938:Caco-2 Cells; D002762:Cholecalciferol / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics; D002784:Cholesterol / Q000097:blood / Q000493:pharmacokinetics; D020895:Enterocytes / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D007408:Intestinal Absorption / Q000187:drug effects*; D007413:Intestinal Mucosa / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008823:Micelles; D010840:Phytosterols / Q000737:chemistry / Q000494:pharmacology*; D019518:Postprandial Period; D012855:Sitosterols / Q000494:pharmacology; D014807:Vitamin D / Q000494:pharmacology*
chemical_list: D008823:Micelles; D010840:Phytosterols; D012855:Sitosterols; D014807:Vitamin D; D002762:Cholecalciferol; C025473:gamma-sitosterol; D002784:Cholesterol