Here are some of the recent posts on this topic...
Re: CCSVI and CCVBP
Dose-related effects of vitamin D on immune responses in CIS
MS birth month link dismissed
Does birth month matter?
Study suggests babies' birth month may affect risk of MS
Vitamin D Abstracts ECTRIMS 2012
Re: UV-B therapy
Analysis backs birth-month effect in MS
The vitamin D relationship
Vitamin D3 for MS & immune-mediated diseases
