I would advise against using vit D, because it is immunosuppressive. I have heard some people mention that it helped much with their fibropains, and this points to its immunosuppressivity. It's similar to HC and mercury, giving you a false feeling that everything is ok. Lowering Vit D is specifically a part of the MP (Marshall protocol), whose aim is to mobilize the immune system to kill off the pathogens.

It would only be useful to take it if you want to slow down your recovery, and get some relief of the pains, which isn't a bad idea at least in the beginning.

http://www.sciencedaily.com/releases/2008/01/080125223302.htm

There are more research papers around demonstrating that vit D is harmful.