With the consideration that it was only a 12 patient/28 week trial, I'm not sure how conclusive I would consider that evidence.
i have a great table comparing various studies of some truly idiotic d3 daily intakes over weeks months and years, with associated serum levels of d3, and where it was measured, the calcium level as well. these are not studies with big n values, but when you look at them side by side it's pretty interesting.
Then again, to date nothing has ever shown conclusively that there is a direct link between low Vit D levels and MS and if there were a provable direct link, that it's a causative factor and not secondary result of the ongoing MS disease process.
there are certainly statistical studies of risk in ms, for instance the military study, where the subjects in the highest quintile ie levels over 100 nmol/L had the lowest risk of ms.