Background: Current evidence suggests that sun exposure and vitamin D intake, during childhood and adolescence, are associated with a reduced risk of multiple sclerosis (MS).
However, the role of these environmental agents in the timing of disease symptom onset remains to be investigated.
Methods: Using a cross-sectional study design, we recruited participants from the Veterans Health Administration – Multiple Sclerosis Surveillance Registry.
Self-reported histories of residential locations, sun exposure and intake of vitamin D were used to estimate vitamin-D-related exposures.
Multivariable linear regression analysis was used to examine the associations between these variables and age at MS onset.
Results: Among veterans with relapsing MS who resided in low-to-medium solar radiation areas (n = 540),
• Low sun exposure in the fall/winter during the ages of 6-15 years was significantly associated with earlier symptom onset by 2.1 years (p = 0.02).
• Intake of cod liver oil [rich source of vitamin D] during the same age period was associated with later onset of MS symptoms by 4 years (p = 0.02).
Conclusions: The current study:
• Provides evidence for an association between vitamin-D-related exposures during childhood and early adolescence and the timing of MS symptom onset,
• And supports vitamin D as a potential modulator of the clinical course of this disease.
Source: Neuroepidemiology, Dec 16, 2010; 36(1):39-45. PMID: 21160231, by McDowell TY, Amr S, Culpepper WJ, Langenberg P, Royal W, Bever C, Bradham DD. MS Center of Excellence-East, Baltimore VA Medical Center, Baltimore, Maryland; Departments of Epidemiology and Public Health and Neurology, school of Medicine, and Department of Pharmaceutical Health Services Research, School of Pharmacy, University of Maryland, Baltimore; Department of Preventive Medicine and Public Health, School of Medicine-Wichita, University of Kansas, Wichita, Kansas, USA. [Email: firstname.lastname@example.org]