Table 3.
Participants’ general characteristics of the intervention study (n = 46)
| Vitamin C | Placebo | P value | |||||
|---|---|---|---|---|---|---|---|
| Total | Men | Women | Total | Men | Women | ||
| No. of subjects | 24 | 14 | 10 | 22 | 12 | 10 | 0.79 |
| Age (year) | 24.6 ± 3.5 | 24.9 ± 3.6 | 24.1 ± 3.5 | 23.7 ± 1.9 | 24.0 ± 2.0 | 23.3 ± 1.8 | 0.27 |
| BMI (kg/m2) | 22.6 ± 3.0 | 24.2 ± 2.6 | 20.3 ± 1.9 | 22.3 ± 3.3 | 23.5 ± 2.0 | 20.8 ± 4.1 | 0.74 |
| Occupation | 0.89 | ||||||
| Undergraduate student (n) | 17 | 10 | 7 | 17 | 9 | 8 | |
| Graduate student (n) | 3 | 2 | 1 | 3 | 2 | 1 | |
| Employee (n) | 4 | 2 | 2 | 2 | 1 | 1 | |
| Current smoker (n) | 1 | 1 | 0 | 3 | 2 | 1 | 0.60 |
| Dietary supplement user (n) | 3 | 3 | 0 | 2 | 2 | 0 | > 0.99 |
| Protein | 2 | 2 | 0 | 1 | 1 | 0 | |
| Vitamin D | 1 | 1 | 0 | 1 | 1 | 0 | |
| Physical activity (MET-min/week) | 2057 ± 1369 | 2219 ± 1205 | 1831 ± 1612 | 1889 ± 1379 | 2022 ± 1354 | 1730 ± 1465 | 0.68 |
| Serum vitamin C concentration (μmol/L) | 42.5 ± 11.7 | 41.5 ± 12.7 | 43.9 ± 10.6 | 40.2 ± 17.2 | 35.0 ± 10.8 | 46.4 ± 21.6 | 0.59 |
| Daily vitamin C intake (mg/day) | 41.3 ± 43.8 | 53.2 ± 14.0 | 24.7 ± 17.0 | 52.5 ± 57.8 | 48.1 ± 43.6 | 57.8 ± 73.6 | 0.46 |
Values are mean ± SD or categorical total
P values were obtained by comparing the vitamin C group (n = 24) with the placebo group (n = 22) using an unpaired t test, a Pearson’s Chi-square test, or a Fisher’s exact test