Vitamin D and multiple sclerosis: epidemiology, immunology, and genetics
Current Opinion in Neurology, 05/20/2012 Clinical Article
Simon KC et al. – Research on the nature of the association between vitamin D and multiple sclerosis (MS) risk and progression continues to progress; however, additional research on the timing and dose–response relationship will be crucial for designing future prevention and treatment trials.

Evidence continues to accumulate supporting a protective role for vitamin D in MS risk and progression.
Notable recent findings are that high 25–hydroxyvitamin D [25(OH)D] at the time of a first demyelinating event predicts a lower MS risk and a decreased risk of MS among offspring whose mothers had high predicted 25(OH)D levels.
While a small vitamin D intervention study did not find an association between vitamin D and MS progression, this study had little statistical power, and larger trials will be needed to assess the therapeutic potential of vitamin D.
Recent immunological studies also show modulation of the immune system by vitamin D that may be favorable for preventing or slowing the progression of MS.
The demonstration that rare variants in CYP27B1, which encodes the enzyme that converts vitamin D to its active form, are strongly associated with MS risk supports a causal role of vitamin D deficiency as a risk factor for MS.

(I am a member of the PD forum, found this review on MS.)

My neuro thinks my 5000iu/daily is higher than he would prescribe, but didn't tell me to change it.

Thank you for the article!

I also take 5000iu capsule daily of D3.

Me, too! I'll never be deficient in D3....that's for sure!

Took 8000/day for a month. Felt great. Blood level was high 120's. That was a yr or so ago, dropped it back to 2000/day, level hangs in the 80's but MS is kicking my ---. Time to get back on at least 5000/day. Just don't get blood level over 150 cause I read close to 200 & organ failure's possible.