Sun Exposure, Vitamin D Intake and Progression to Disability among Veterans with Progressive Multiple Sclerosis.
Neuroepidemiology. 2011 Aug 5;37(1):52-57.
McDowell TY, Amr S, Culpepper WJ, Langenberg P, Royal W, Bever C, Bradham DD.
MS Center of Excellence-East, Baltimore VAMC, Baltimore, Md., USA.
Background: Early life events have been suggested to influence multiple sclerosis (MS) susceptibility, and to potentially modulate its clinical course. We assessed vitamin D-related exposures from childhood to disease onset and their associations with MS progression.
Methods: Among veterans in the Multiple Sclerosis Surveillance Registry, 219 reported having the progressive form and met the inclusion criteria. Participants reported their past sun exposure, vitamin D-related intake and age at disability milestones using the Patient-Determined Disease Steps (PDDS). The Cox proportional hazards model was used to examine the association between vitamin D-related exposures and time (years) to disability.
Results: Low average sun exposure in the fall/winter before disease onset was associated with an increased risk of progressing to a PDDS score of 8 (hazard ratio, HR: 2.13, 95% confidence interval, CI: 1.20-3.78), whereas use of cod liver oil during childhood and adolescence was associated with a reduced risk (HR: 0.44, 95% CI: 0.20-0.96).
Conclusions: These results suggest that exposure to vitamin D before MS onset might slow disease-related neurodegeneration and thus delay progression to disability among patients with the progressive subtype.
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