title: Use of water-miscible retinyl palmitate as markers of chylomicrons gives earlier peak response of plasma retinyl esters compared with oil-soluble retinyl palmitate.
abstract: Delayed peak response of plasma retinyl esters (RE) relative to plasma triacylglycerols (TAG) and apolipoprotein (Apo) B-48 responses following a fat load supplemented with vitamin A raised doubts about the use of vitamin A to label dietary-derived lipids and lipoproteins. The present study compared the use of water-miscible and oil-soluble retinyl palmitate (RP) as markers of dietary-derived lipoproteins in healthy subjects along with the measurements of postprandial plasma TAG and ApoB-48 responses to investigate whether the delayed peak response observed was due to delayed intestinal output of RE from oil-based solutions. Nine healthy female subjects were given a standard test meal containing a dose (112 mg) of RP in either water-miscible or oil-soluble form in random order, on two separate occasions after a 12 h overnight fast. The results showed that the mean plasma RE concentrations reached a peak significantly later than mean plasma TAG and ApoB-48 concentrations when oil-soluble RP was consumed, whereas plasma RE peaked earlier relative to plasma TAG and ApoB-48 responses when water-miscible RP was used. The results suggested a more rapid absorption with a significantly higher and earlier peak response of plasma RE when water-miscible RP was consumed. This was in contrast to the delayed initial appearance and later sustained higher concentrations of plasma RE during the late postprandial period when oil-soluble RP was consumed. The RE response to the water-miscible RP showed better concordance with plasma TAG response than that of oil-soluble RP.
authors.affiliation: Hugh Sinclair Unit of Human Nutrition, School of Food Biosciences, University of Reading, Reading, Berkshire RG6 6AP, UK.
authors.forename: K D
authors.initials: KD
authors.lastname: Silva
authors.forename: C M
authors.initials: CM
authors.lastname: Williams
authors.forename: J A
authors.initials: JA
authors.lastname: Lovegrove
mesh_terms: D000328:Adult; D001055:Apolipoproteins B / Q000378:metabolism; D019540:Area Under Curve; D002914:Chylomicrons / Q000378:metabolism*; D004041:Dietary Fats / Q000008:administration & dosage*; D004224:Diterpenes; D005260:Female; D006801:Humans; D008074:Lipoproteins / Q000097:blood*; D019518:Postprandial Period; D000084562:Retinyl Esters; D012995:Solubility; D013997:Time Factors; D014280:Triglycerides / Q000378:metabolism; D014801:Vitamin A / Q000031:analogs & derivatives*
chemical_list: D001055:Apolipoproteins B; D002914:Chylomicrons; D004041:Dietary Fats; D004224:Diterpenes; D008074:Lipoproteins; D000084562:Retinyl Esters; D014280:Triglycerides; D014801:Vitamin A; C014794:retinol palmitate