"Game changers" is both broad and specific. There are doctors that specialize in this, customizing things based on diet and the individual MSer. Dr. Terry Wahls of the famous Wahls Protocol diet (https://www.amazon.com/Wahls-Protocol-Autoimmun...) sort of falls into this category. So a lot of this is "what supplements" make you *feel better?*

But the only one I know of that is across-the-board scientifically proven is vitamin D. (Others are symptom/individually specific.)

Myself, I'm pretty much following this recommendation (https://www.direct-ms.org/nutrition/supplements/).

My neurologist put me on biotin 600 mg, and alpha lipoic acid. It seems to help.

This book is excellent and easy to read. "Minding Your Mitochondria"
by Terry Wahls, MD . . she is a doctor who has MS and got herself out of a wheelchair by learning about nutrition.
She talks about all the nutrients our brain needs on a cellular level and why we need them. It might help! I think it could and we are better if we do this as much as we can as opposed to not doing it.
some herbs and vitamins needed are:
Omega 3, 6 and 9
CO-Q 10
Iodine (in kelp)
Resveratrol
Vitamin D and B complex and other B's
alpha lipoic acid
antioxidants (responsible for waste removal)
zinc
MSM
dark green leafy vegetables (contain all the vitamins, naturally)
and more!! lots more . .
it is an easy read and there is few pages that charts the nutrients, amount needed and food sources.
use food sources first before supplements. (when and if you can)
It is an easy reference tool.

I hope you like it!

B12

It’s a little hard to follow a diet when you can’t even shop to get the foods needed for the diet.