Abstract:
The relative enrichment of skin sebaceous gland lipids with deuterium-labeled
α-tocopherol was compared with plasma enrichment to evaluate the
delivery of vitamin E to skin. For the first week of this study, each subject
consumed a daily dose of deuterated vitamin E (150 mg of an equimolar mixture of
RRR-α-[5-(C²H₃)]-(d₃) and all rac-α-[5,7-(C²H₃)₂]-(d₆) tocopheryl acetates) with
breakfast. Blood was drawn and skin lipids were collected daily for two weeks,
then every other day for the following two weeks. Labeled and unlabeled vitamin
E analysis was carried out using liquid chromatography and mass spectrometry
(LC/MS). Skin cholesterol, plasma cholesterol and triglycerides were measured to
evaluate changes in vitamin E levels relative to lipid content. While d₃ and
d₆-α-tocopherols were found in plasma 24 h after the first dose, d₃-α-tocopherol
was only detected in the skin sebaceous gland secretions after 1 week of
supplementation. This data suggests a skin-mediated delivery system for vitamin E into skin lipid secretions. This finding is also supported by the observation that the
ratio of α-to γ-tocopherol was greater in the skin than in the plasma.
