Although vitamin C supplements were consumed for health maintenance and fatigue recovery, the effects of high doses of vitamin C supplement remains controversial. Our study performed the effects of 100 mg and 2,000 mg vitamin C supplements on plasma and urinary vitamin C concentration in Korean women. Twenty-four women completed the 4 weeks intervention. Anthropometric data, plasma and urinary vitamin C concentrations, superoxide dismutase activity, thiobarbituric acid reactive substance (TBARS) level, and fatigue severity scale (FSS) were collected, and the statistical analyses compared between- and within-group findings at pre- and post-intervention. Concentrations of vitamin C in plasma and urinary excretion were significantly increased with 100 mg and 2,000 mg of vitamin C supplementation (p < 0.050). TBARS level was decreased significantly with 2,000 mg of vitamin C supplementation (p < 0.050). In addition, FSS was declined significantly in 100 mg of vitamin C supplementation group (p < 0.050). Our result showed that vitamin C supplementation of either 100 mg or 2,000 mg led to an increase in vitamin C concentrations in plasma and vitamin urinary excretion but not statistically significant among groups. TBARS level was decreased in 2,000 mg and FSS was decreased in 100 mg of vitamin C supplementation in Korean women. We suppose that additional clinical trial is needed to examine the effects of vitamin C supplements for a wide range of doses on plasma and urinary vitamin C concentrations in Korean.