Use of cod liver oil and multivitamin supplements by baseline characteristics in the Nord-Trøndelag Health Study in 1995–1997 to 2006–2008 (N=16 952)
| Reference group# | Cod liver oil only | Multivitamin supplements only | Use of both | |
| Subjects | 13 742 (81) | 1163 (7) | 997 (6) | 1050 (6) |
| Age at baseline years | 38.8±8.8 | 41.6±8.1 | 40.4±8.9 | 41.9±8.6 |
| Body mass index kg·m−2 | 25.7±3.8 | 25.5±3.5 | 25.4±3.9 | 25.4±3.7 |
| HADS | ||||
| Anxiety | 4.0±3.1 | 4.2±3.2 | 4.7±3.5 | 4.7±3.5 |
| Depression | 2.9±2.7 | 2.9±2.7 | 3.3±2.8 | 3.1±2.9 |
| Female sex | 7229 (52.6) | 657 (56.5) | 794 (79.6) | 741 (70.6) |
| Current smoking | 3827 (27.9) | 239 (20.6) | 310 (31.1) | 264 (25.1) |
| Physical activity <1 h per week | 3140 (22.9) | 202 (17.4) | 181 (18.2) | 179 (17.1) |
| Education <10 years | 2511 (18.3) | 218 (18.7) | 181 (18.2) | 172 (16.4) |
| Social benefit recipient | 2371 (17.3) | 189 (16.3) | 241 (24.2) | 268 (25.5) |
| Having economic difficulty | 4384 (31.9) | 274 (23.6) | 357 (35.8) | 295 (28.1) |
| Family history of asthma | 2254 (16.4) | 192 (16.5) | 188 (18.9) | 190 (18.1) |
| Alcohol consumption ≥5 times per month | 1865 (13.6) | 182 (15.7) | 126 (12.6) | 152 (14.5) |
| Any chronic disease at baseline | 1590 (11.6) | 194 (16.7) | 202 (20.3) | 249 (23.7) |
Data are presented as n (%) or mean±sd. HADS: Hospital Anxiety and Depression Scale. #: nonusers or those with a daily intake of cod liver oil or multivitamin supplements for <3 months.