Plasma Level and Urinary Excretion of Vitamin C after Oral Administration of 1000 mg and 2000 mg of vitamin C

Abstract

The plasma concentration-time profile and urinary excretion of vitamin C after the oral administration of a single dose (1000 or 2000 mg) was examined using six healthy males (25-29 years) in a two-period crossover trial. The mean T_<max> (h) was 3 for both 1000 mg and 2000 mg. The mean C_<max> (mg/100 ml) was 1.13 for 1000 mg and 1.55 for 2000 mg (based on concentration above the initial value). The mean AUC (mg.g/100 ml, 0-24 h) was 11.16 for 1000 mg and 17.12 for 2000 mg. The plasma concentration-time profile could be simulated by a one-compartment model with first-order absorption. Ka (h^<-1>) were 0.31-0.33 and Ke (h^<-1>) were 0.31-0.33. V/F (liter) was 35 for 1000 mg and 49 for 2000 mg. The mean amount (mg, above the initial value) excreted in the 24-h urine was 269 for 1000 mg and 362 for 2000 mg. The percentage of the dose excreted was 27% for 1000 mg and 18% for 2000 mg.