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Oral Supplementation with All‐Rac ‐ and RRR ‐α‐Tocopherol Increases Vitamin E Levels in Human Sebum after a Latency Period of 14‐21 Days
Author(s) -
EKANAYAKEMUDIYANSELAGE SWARNA,
KRAEMER KLAUS,
THIELE JENS J.
Publication year - 2004
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1196/annals.1331.017
Subject(s) - bioavailability , medicine , endocrinology , chemistry , vitamin e , vitamin , alpha (finance) , tocopherol , squalene , alpha tocopherol , antioxidant , biology , pharmacology , biochemistry , surgery , construct validity , patient satisfaction
A bstract : In human skin, highest α‐tocopherol levels are found in facial sebum. We hypothesized that the bioavailability of vitamin E in human skin is, at least in part, dependent on sebaceous gland secretion. To test this, 24 volunteers were subjected to a randomized daily supplementation with either 400 mg RRR ‐α‐tocopheryl acetate ( RRR ‐α‐toc) or 400 mg all‐rac ‐α‐tocopheryl acetate ( all‐rac ‐α‐toc) for 14 days. Fasting blood samples, facial sebum samples, and lower‐arm skin‐surface lipids (SSL) were taken at time‐points between 0‐21 days. Samples were analyzed by HPLC for α‐tocopherol and squalene concentrations. Increased serum α‐tocopherol levels were detectable as early as 12 h after supplementation of RRR ‐α‐toc or all‐rac ‐α‐toc and peaked on day 7. No significant changes were observed in lower‐arm SSL. Remarkably, while unchanged until day 14, α‐tocopherol sebum levels were increased on day 21 in both the RRR ‐α‐toc and the all‐rac ‐α‐toc group by 87% and 92%, respectively. With respect to dietary supplementation of vitamin E and its bioavailability in human skin, these results suggest that (1) sebaceous gland secretion is a relevant delivery mechanism; (2) the bioavailabilities of RRR ‐α‐toc and the all‐rac ‐α‐toc are similar; and (3) significant accumulation requires a daily supplementation period of at least 2‐3 weeks.