BACKGROUND: Low vitamin D levels have been associated with an increased risk of multiple sclerosis (MS), although it remains unknown whether this relationship varies by age.
OBJECTIVE: The objective of this paper is to investigate the association between vitamin D3 supplementation through cod liver oil at different postnatal ages and MS risk.
METHODS: In the Norwegian component of the multinational case-control study Environmental Factors In Multiple Sclerosis (EnvIMS), a total of 953 MS patients with maximum disease duration of 10 years and 1717 controls reported their cod liver oil use from childhood to adulthood.
RESULTS:Self-reported supplement use at ages 13-18 was associated with a reduced risk of MS (OR 0.67, 95% CI 0.52-0.86), whereas supplementation during childhood was not found to alter MS risk (OR 1.01, 95% CI 0.81-1.26), each compared to non-use during the respective period. An inverse association was found between MS risk and the dose of cod liver oil during adolescence, suggesting a dose-response relationship (p trend = 0.001) with the strongest effect for an estimated vitamin D3 intake of 600-800 IU/d (OR 0.46, 95% CI 0.31-0.70).
CONCLUSIONS: These findings not only support the hypothesis relating to low vitamin D as a risk factor for MS, but further point to adolescence as an important susceptibility period for adult-onset MS
What this study does is that it looks at cod liver oil supplementation and the risk of subsequently developing MS. The data suggests that risk is not reduced if you just supplement during childhood but if you supplement during adolescence then the risk of MS was halved. The more cod liver oil, hence vitamin D you had the lower the risk of MS. However the supplements were lower than suggested currently doses.
This fits with the migration studies which looks at risk if you migrate before or after the age of 15 from low to high MS risk areas and suggests you encounter the MS risk problem in adolescence. Is this EBV, if so has the Charcot project 1 missed the window?