Steady-state turnover and body pool of ascorbic acid in man.

The time course of radioactivity in plasma and urine after oral administration of a single dose of (1-14C)ascorbic acid has been followed in healthy nonsmoking male volunteers. The investigation was carried out under steady state conditions with regard to ascorbic acid intake (30 to 180 mg/day). Using pharmacokinetic principles, turnover, pool size, and rates of metabolism and excretion could be calculated. It was found that the half-life of ascorbic acid was inversely related to the dosage and that the pool could be increased to about 20 mg/kg bodyweight by increasing the dosage. It was concluded that on a daily intake of about 100 mg ascorbic acid this pool size would be reached in 95% of the population.