Neurology. 2004 Jan 13; 62(1): 60-5
Munger KL, Zhang SM, O'Reilly E, Hernan MA, Olek MJ, Willett WC, Ascherio A.
Department of Nutrition, Harvard School of Public Health, 665 Huntington Ave., Boston, MA 02115, USA.
A protective effect of vitamin D on risk of multiple sclerosis (MS) has been proposed, but no prospective studies have addressed this hypothesis.
Dietary vitamin D intake was examined directly in relation to risk of MS in two large cohorts of women: the Nurses' Health Study (NHS; 92,253 women followed from 1980 to 2000) and Nurses' Health Study II (NHS II; 95,310 women followed from 1991 to 2001).
Diet was assessed at baseline and updated every 4 years thereafter.
During the follow-up, 173 cases of MS with onset of symptoms after baseline were confirmed.
The pooled age-adjusted relative risk (RR) comparing women in the highest quintile of total vitamin D intake at baseline with those in the lowest was 0.67 (95% CI = 0.40 to 1.12; p for trend = 0.03).
Intake of vitamin D from supplements was also inversely associated with risk of MS; the RR comparing women with intake of >or=400 IU/day with women with no supplemental vitamin D intake was 0.59 (95% CI = 0.38 to 0.91; p for trend = 0.006).
No association was found between vitamin D from food and MS incidence.
These results support a protective effect of vitamin D intake on risk of developing MS.