On the absorption of ascorbic acid in man.

The daily intake of ascorbic acid with the diet was strongly restricted in seven healthy non-smoking males and 90 to 180 mg of ascorbic acid were orally supplemented. After an equilibration period of three weeks about 5 muCi of (1-14C) ascorbic acid was orally administered with carrier (30 mg or 60 mg). The daily intake was then increased to 4 X 1000 mg and the cumulative excretion of radioactivity in the urine measured over a period of 10 days. The average absorption was estimated to amount to 80-90% of the dose.