Table 3.
Association between average daily intake of vitamin D3 through monthly supplemented cod liver oil in the winter during adolescence (ages 13–19) and MS risk for age at disease onset >19.
| Cod liver oil(ts/month) | Vitamin D3(IU/day) | Cases n (%) | Controls n (%) | ORa | 95% CI |
|---|---|---|---|---|---|
| Noneb | – | 525 (66.0) | 784 (56.1) | 1.00 | – |
| 1–15 | ⩽ 200 | 79 (9.9) | 160 (11.5) | 0.74 | 0.55–0.99c |
| 16–30 | 201–400 | 55 (6.9) | 125 (9.0) | 0.68 | 0.48–0.95c |
| 31–45 | 401–600 | 14 (1.8) | 38 (2.7) | 0.58 | 0.31–1.08 |
| 46–60 | 601–800 | 32 (4.0) | 104 (7.4) | 0.46 | 0.31–0.70d |
| >60 | >800 | 90 (11.3) | 186 (13.3) | 0.77 | 0.58–1.02 |
MS: multiple sclerosis; n: count; ts: teaspoons; IU: international units; OR: odds ratio; CI: confidence interval.
All estimates adjusted for age and sex; p-trend for association = 0.001, OR (95% CI) = 0.91 (0.87–0.96). Adjusting in addition for smoking before disease onset, history of infectious mononucleosis, sun exposure, body shape at age 15, education, and consumption of fatty fish: p trend = 0.025, OR (95% CI) = 0.94 (0.89–0.99). The effect estimate did not materially change when adjusting in addition for supplementation during adolescence in the summer.
Reference group consists of those who reported neither an intake of cod liver oil liquid nor capsules.
P value < 0.05.
P value < 0.0001.