Bioavailability of vitamin E compounds in lambs.
A study was carried out to assess the bioavailabilities of several forms of vitamin E in lambs. A total of 40 lambs was allotted to eight dietary groups of five each and supplemented or not daily for 60 d with equimolar amounts of different vitamin E compounds as follows: 1) control, no supplemental vitamin E, 2) DL-alpha-tocopheryl acetate, 3) D-alpha-tocopheryl acetate, 4), D-alpha-tocopheryl succinate, 5) D-alpha-tocopheryl polyethylene glycol 1,000 succinate (TPGS), 6) DL-alpha-tocopheryl nicotinate, 7) DL-alpha-tocopheryl nicotinate+ TPGS, or 8) D-alpha-tocopheryl acetate + TPGS. During these 60 d, serum alpha-tocopherol concentrations in the control lambs remained constant and lower (P less than .05) than in lambs that received all treatments. Various indices of bioavailability, including Cmax-C(i) (concentration maximum-concentration initial), Ct-C(i) (concentration terminal-concentration initial), areas under the serum concentrations profiles, and pooled increment were higher (P less than .05) with D-alpha-tocopheryl acetate+ TPGS than in the other groups, suggesting a synergism between these forms. No such effect was observed between nicotinate and TPGS. For the TPGS, a water-soluble form of vitamin E, the indices of bioavailability were lower (P less than .05) than for the other groups. D-alpha-tocopheryl acetate resulted in a bioavailability that outranked all the other forms of vitamin E, except those of D-alpha-tocopheryl acetate + TPGS. A slightly higher bioavailability index was observed for D-alpha-tocopheryl succinate than for DL-alpha-tocopheryl nicotinate.(ABSTRACT TRUNCATED AT 250 WORDS)
Hidiroglou
N
N
Department of Surgery, East Tennessee State University, Johnson City 37604.
McDowell
L R
LR
Papas
A M
AM
Antapli
M
M
Wilkinson
N S
NS
D000042:Absorption; D000284:Administration, Oral; D000818:Animals; D001682:Biological Availability; D008297:Male; D009539:Nicotinic Acids / Q000008:administration & dosage / Q000493:pharmacokinetics; D011092:Polyethylene Glycols; D011897:Random Allocation; D012756:Sheep / Q000378:metabolism*; D024505:Tocopherols; D014810:Vitamin E / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D024502:alpha-Tocopherol / Q000031:analogs & derivatives*
D009539:Nicotinic Acids; D014810:Vitamin E; D011092:Polyethylene Glycols; C012581:alpha-tocopheryl nicotinate; D024502:alpha-Tocopherol; C014225:tocophersolan; D024505:Tocopherols