Comparison of patient characteristics at baseline by treatment group
| Subject characteristics | Vitamin D3 | Placebo | p Value* |
| Number of participants | 21 | 19 | NA |
| Age (years) | 25.8 (7.6) | 29.4 (13) | 0.2865 |
| Male gender (%) | 71.4 | 57.9 | NA |
| Ethnicity (% white) | 95.2 | 84.2 | NA |
| Smokers (%) | 23.8 | 36.8 | NA |
| Pack/years | 17.5 (9.1) | 23 (12.7) | 0.4272 |
Data expressed as mean and SD.
*Compared by unpaired t-test.
NA, not applicable.