Absorption of water-miscible forms of vitamin E in a patient with cholestasis and in thoracic duct-cannulated rats.

ABSTRACT

Oral administration of vitamin E (100 mg tocopherol X kg-1 X day-1) as tocopheryl polyethylene glycol 1000 succinate (TPGS) to a child with congenital hepatic cholestasis (unresponsive to oral administration of dl-alpha-tocopheryl acetate) promoted an increase of tocopherol in plasma and adipose tissue while tocopheryl acetate emulsified with medium chain triglycerides and polysorbate 80 (MCT-E) did not. alpha-Tocopherol absorption, quantitated in thoracic duct-cannulated rats receiving intraduodenal infusions of soybean oil and saline, was similar for TPGS, MCT-E, and dl-alpha-tocopheryl acetate; gamma-tocopherol absorption from soybean oil was not affected by the presence of the supplemental alpha-tocopherol. Following bile duct ligation in one rat, TPGS promoted the absorption of alpha-tocopherol while absorption of gamma-tocopherol from soybean oil was decreased 30 fold, demonstrating that TPGS, which forms a micellar solution, delivers alpha-tocopherol through the unstirred water layer to enterocytes, while free tocopherol (alpha or gamma) absorption requires the presence of bile salts.