Kristi, I'm quite surprised you were prescribed D2 as opposed to D3 (aka Cholecalciferol). D3 is the equivalent to the "sunshine" factor and is processed in the body as a hormone -- it's specifically that form that's been the hot topic.

I started reading a lot about D3 after I was dxed and have been taking a little over 3,000 IUs daily for at least 9 months. (I ADD UP the D in my calcium and mult-vitamin and then supplement with two 1,000 capsules made by Jarrow.) Vitamin D can build up in the body and can be toxic so your levels should be monitored, as well as your liver function. I don't know if my levels were low before I started supplementing but my endocrinologist tested me a few months ago and even with the amount I'm taking, I was still within normal range (and my liver function was fine). However, I will continue to be monitored, having these tests repeated in future blood work. My endo explained to me that for some reason, they're finding that those high 50,000 IU doses weekly do not seem to present the same problems as high doses building up over time.

The RDA UL for "healthy" people has been raised to 600 IUs. There have been several studies about vitamin D (D3 specifically) possibly being helpful with various neurological disorders, not only MS (and not only in terms of prevention). I know many people with MS in the U.S. whose doctors have been recommending (if not prescribing) vitamin D3 to their patients even if their levels are not low. Most of the things I've read about using this supplement like a "drug" recommend up to 4,000 IUs daily but to reduce intake in the summer or if you live in a sunny climate year round. Again, do be careful though -- do your own research, speak to your doctors and if you DO take it, have your D levels and liver function tested periodically.