Effects of Clinical Doses of Phenobarbital on Blood and Urine Ascorbic Acid in Human Subjects

Abstract

There was no significant change in whole blood, plasma, or urinary excretion of ascorbic acid following administration of 180 mg of phenobarbital daily to human subjects. Twenty-five mg of crystalline ascorbic acid daily is insufficient to maintain whole blood or plasma values when the subjects take an ascorbic acid-free diet.