Can changes in hydrophobicity increase the bioavailability of alpha-tocopherol?
BACKGROUND
Bioavailability of fat-soluble vitamins from conventional oral supplements is insufficient in some conditions in which fat digestion and absorption are chronically impaired (e. g. cystic fibrosis).


OBJECTIVE
We used a water-soluble form of fatsoluble vitamin E (AQUANOVA solubilisate) to create a nutritional supplement (NS) in the form of vitaminized gummi bears (with micellised water-soluble alpha-tocopheryl acetate (100 IU) and 400 mg crystalline vitamin C). We assessed the bioavailability of the NS in comparison to conventional preparations.


METHODS
The trial consisted of three study days (d0: NS sucked; d10: NS swallowed; d20: reference products swallowed). A total of 14 subjects (6 male/8 female), aged 25.3 (22.7-35.3) years, BMI 24.3 (19.0-31.7) kg/m(2) participated in the study. They had blood samples drawn after fasting for >or=12 hours and then 1, 5, 15, 30, 60, 120, 180, 240, 300 and 320 minutes after ingesting the vitamins. HPLC and a colorimetric method were used to determine vitamin E and vitamin C, respectively. Areas under the curve (AUC(0-320min)) and maximum increases in plasma concentrations (Delta concentration) were calculated to assess bioavailability.


RESULTS
The AUCs(0-320min) of alpha-tocopherol from d0 were significantly larger (p = 0.016) when compared to d20. Moreover, the maximum increase in alpha-tocopherol plasma concentrations was significantly higher for d0 (p = 0.023) and d10 (p = 0.002) when compared to d20.


CONCLUSIONS
Short-term bioavailability of AQUANOVA micellised fat-soluble vitamin E from our NS was significantly higher than from regular supplements. The NS will now be tested for its clinical efficacy in a randomized double-blind controlled intervention trial with CF patients.
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Evelyn I
EI
University of Hohenheim, Institute of Biological Chemistry and Nutrition, Garbenstr. 30, 70593 Stuttgart, Germany.
Frindt
Claudia
C
Oćenásková
Erika
E
Nohr
Donatus
D
Stern
Martin
M
Biesalski
Hans K
HK
D000328:Adult; D019540:Area Under Curve; D001682:Biological Availability; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003124:Colorimetry / Q000379:methods; D018592:Cross-Over Studies; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D008297:Male; D012995:Solubility; D014815:Vitamins / Q000097:blood / Q000493:pharmacokinetics*; D024502:alpha-Tocopherol / Q000097:blood / Q000493:pharmacokinetics*
D014815:Vitamins; D024502:alpha-Tocopherol