Distribution of baseline characteristics in the cohort and subcohort of the HUNT2 study (1995–1997)
| Cohort | Subcohort# | |
| Subjects n | 54 580 | 5546 |
| Age years | 49.2±16.6 | 49.1±16.6 |
| Season-standardised 25(OH)D level nmol·L−1 | 48.3±17.1 | |
| Lung cancer cases n | 676 | 77 |
| Sex | ||
| Female | 52.7 | 52.8 |
| Male | 47.3 | 47.2 |
| Smoking | ||
| Never | 42.3 | 42.5 |
| Ever | 55.8 | 55.4 |
| Unknown | 1.9 | 2.1 |
| Family history of cancer | ||
| No | 74.5 | 74.1 |
| Yes | 25.5 | 25.9 |
| Education years | ||
| <10 | 33.6 | 32.9 |
| ≥10 | 61.8 | 62.5 |
| Unknown | 4.6 | 4.6 |
| Economic difficulties | ||
| No | 49.8 | 51.0 |
| Yes | 21.8 | 21.1 |
| Unknown | 28.3 | 27.9 |
| Body mass index kg·m−2 | ||
| <25 | 39.8 | 40.6 |
| ≥25 | 59.4 | 58.8 |
| Unknown | 0.7 | 0.6 |
| Physical activity | ||
| Inactive | 21.4 | 21.1 |
| Active | 48.8 | 49.0 |
| Unknown | 29.9 | 29.8 |
| Alcohol consumption | ||
| Never | 33.6 | 32.9 |
| ≥1 times per month | 58.0 | 59.0 |
| Unknown | 8.4 | 8.1 |
| Chronic bronchitis | ||
| No | 94.6 | 95.0 |
| Yes | 3.4 | 3.4 |
| Unknown | 2.0 | 1.7 |
Data are presented as mean±sd or %, unless otherwise stated. 25(OH)D: 25-hydroxyvitamin D. #: those with measured serum 25(OH)D levels and genotype information.