It appears that after much study that the US Veterans Admin. has decided that Vitamin D does indeed help MS
The VA Multiple Sclerosis Center of Excellence has a video on the web July 2011
The 2.5 minute video is just people talking, but has the following graph
from an unknown study - perhaps in 2011
The horizontal axis shows the amount of vitamin D in the blood BEFORE getting MS
The vertical access shows the relative risk of subsequently getting Multiple Sclerosis
Vitamin D < 66 nmol (25 ng) Risk =1
Vitamin D 66-74 nmol (25-30 ng) Risk = 0.57
Vitamin D 75-85 nmol (30-34 ng) Risk = 0.57
Vitamin D 84-99 nmol (34-40 ng Risk =0.74
Vitamin D 99-152 nmol (40-61 ng) Risk = 0.30