Plasma tocopherol concentrations in response to supplemental vitamin E.

Normal healthy volunteers were studied after various doses of dl-alpha-tocopherol were ingested on different schedules. Administration of 440, 880, or 1320 mg (400, 800, or 1200 IU) of dl-alpha-tocopherol as a single dose resulted in elevation of plasma alpha-tocopherol concentrations that peaked at 12-24 h. Chronic administration of dl-alpha-tocopherol (440, 880, or 1320 mg/d for 28 d) resulted in a steady state that occurred by days 4-5 of supplementation. Discontinuation of the treatment after day 28 was associated with a decline of plasma alpha-tocopherol, which returned to the pretreatment concentrations between 12 and 20 d. The plasma elevation of alpha-tocopherol was affected by dietary fat intake. Individuals consuming a high-fat diet showed significantly greater plasma alpha-tocopherol concentrations as compared with those fed a low-fat diet. The results of this study indicate that plasma kinetics of alpha-tocopherol are similar when supplements of 440, 880, or 1320 mg dl-alpha-tocopherol are given to normal, healthy individuals.