Marita, good for you finding a natural remedy that is working! I can't speak to the risks of the dosages. Personally, I'd be more concerned with the quality of supplements, and the formulation type. So much to know about bioavailability and related issues. Can you find a good ND? Maybe your doc could advise?
We've kicked the D issue around for years. I maintain that it acts a powerful immune modulator, secosteroid and a vitamin. People here that take large doses seem to react digitally: they either feel much better or much worse. Marshall has done years of research on the vitamin D receptor and has built a healing protocol on avoiding D and pulsing with antibx. I was on it for 3.5 years and it saved my life. A blurb on this on pubmed:
http://www.ncbi.nlm.nih.gov/pubmed/19758226
If you are testing for D levels, make sure they test for both D25 and D1,25. The balance between those is thought to be diagnostic, though I can't advise how as this is tricky territory.
This is a really juicy topic that delves into the D topic and osteo issues. Lots here:
http://www.adrsupport.org/forums/f51...porosis-10179/
In particular, note my 3-25-10 post referencing the amazing work of Phyliss Balch in PDF.