--given your situation, an attempt to use niacin and perhaps more fish oil (and lots of insoluble fiber) to control the cholesterol--nobody with a history of nerve damage, central or peripheral, needs to be on statins, given their propensity for tissue breakdown.
As far as the rest, I suspect you might need a higher dosage of vitamin D3, and I think you would a better magnesium supplement in a higher amount. The general "optimal" ratio of calcium/magnesium is in the 2:1 range, given their electrochemical properties and their tendency to act antagonistically in the body. I don't think you're getting that, given you are using magnesium oxide, which is not well absorbed; a chelated magnesium or magnesium acetate would be more bioavailable.
Have you seen the very long Vitamin D threads at Braintalk on the Vitamin forum and in the Gluten section (which I think would be good to import to the corresponding forums here)?
http://brain.hastypastry.net/forums/...0761#post40761
http://brain.hastypastry.net/forums/...ad.php?t=15249
Reviewing the literature, I am becoming more convinced that many of us--especially us northern latitude types who don't go outside a lot--are walking around with a de facto Vitamin D deficiency, and since D is needed to drive calcium (and to a lesser extent phosphorous) into the bones, this deficiency contributes in a significant way to osteopenia/osteoporosis. I imagine as the demands for bone construction go up, as in those who need to fuse, this can only become more urgent.