you're very welcome drury
25,000 IU at once is not ideal, but it's equivalent to the smallest drop i can currently eke out of the oral syringe i use to dispense my liquid.
a friend is going to get me a smaller syringe so that i can eke out 10,000IU doses, which i personally feel would be a better amount for a single dose. i'd probably do those every three days or so. not forgetting testing to monitor the effect.
you can absolutely overdose on D3. it is a fat soluble vitamin and if serum levels go higher than say, 250 nmol/L, hypercalcemia can result. i don't know if science knows, right now, of any consequences of vit D3 excess, at levels below 250 and not involving hypercalcemia.
i do know from the science available, that patients with levels above 100 nmol/L have the least risk of MS.
NHE's experience is very interesting. i know that when i optimized my mineral status that my body's response to D3 supplementation pretty much tripled compared to previous dose-response.
as for zinc, typical recommendations for ms patients range from 10 to 50 mg / day. having looked at serum levels in healthy controls, i tend to favour a level in the close neighbourhood of 18.2 umol/L. the amount to take per day depends on how close you are to 18.2 to start. unfortunately testing is the best (only?) way to determine an appropriate daily level of supplementation.
FYI, looking at serum uric acid levels can help nail things down - uric acid levels are low in ms patients and appear to be related to zinc status. i found that my uric acid levels normalized when i corrected deficient zinc. it was only later that i realized my d3 absorption had dramatically improved also!
as for b vitamins.. too much b12 at the wrong time of day can disturb sleep. i personally have found that too much folic acid (b9) causes something i call 'phantom itch' (in my case i had switched to a b complex with higher b9 than a previous product).
also i believe it is b6 that can cause neuropathy in both deficiency and excess:
"Several reports show sensory neuropathy at doses lower than 500 mg per day"
i would suggest that a daily b50 or b100 complex should be fine. personally i took up to 300 or 400 mg of b6 daily (along with the rest of the complex in balanced amounts) only briefly in 2006, as part of a modified, reduced, oral only klenner protocol. i was only on the protocol for three days and repaired significant sensory disability, in my hands in particular.
there's more to klenner than b complex however, and a couple years later, i now think the vitamin E aspect of the protocol should not be ignored - regardless of what i have learned since about vitamin E (alpha tocopherol vs E8 complex etc)!
so complicated, fun fun fun :S hehehe