The MS Australia link below actually lists about half a dozen research based links on diet, nutrition and MS, that are worth reading....
"While there is currently little evidence from clinical studies that definitely confirms particular foods or dietary changes can help reduce MS symptoms, there have been a number of studies indicating associations between certain dietary components and MS. There are also many examples of people who are living well with MS through a combination of the right treatment and some simple diet and lifestyle changes.
A well-balanced diet, low in fat and high in fibre, can help stabilise weight and improve bowel health. Adding dietary supplements such as multi-vitamins with minerals, calcium, and vitamin D can also be useful however supplements and vitamins should not replace proper food intake."
MS trust has a pdf specifically for vitamin D: http://www.mstrust.org.uk/downloads/vitamind.pdf
The other week I inadvertently came across a certified US doctor, who was explaining the benefits of a natural supplement program, it seriously looked and sounded legit with all the research quotes, medical logo's etc, the site even had a few compelling video testimonials from diagnosed MSers but then it started going pair shaped, stating how and why neurologist were treating MS completely wrong, and that he absolutely knows what causes MS and why his treatment will cure.....
Hmmmmm lost within all of it was one little line that pointed out, that all of the people in his cure testimonials were actually actors (!) and when you get to the very bottom, you then find out he's actually selling his 'cure' for MS for only $49.95 but wait there's more, buy now at this one time discounted price and you'll also receive.......grrrrrrrrrrr
Try and stick to the information found on any of the MS societies, it's more likely to be accurate and less likely to lead anyone astray!
I have found Magnesium supplements extremely helpful with my muscle spasticity. It has to be the right sort and highly absorbable as I spent years on one kind and it wasn't until my recent time in a rehab hospital that they changed it to a better form of magnesium and wow what a difference it has made.
I also have lots of friends with MS on Magnesium. I was found to be very difficient in it so I guess that's probably why I feel so much better on it. The other supplements I take are Vitamin D and occasionally I take some homeopathic Melatonin to aid my sleep.
I used to be on a truck load of supplements but I did not find any long term benefits with taking them. It also costs a fortune so I try to look at my diet to ensure I eat wholesome foods with all food groups included this can eliminate the need for some supplements.
I take a multivitamin and Vitamin D. None really help MS but your over all health. MSers are not immune to other health problems. It makes life easier if you have few health problems. That is why I am big on a good diet and exercise. When I was first diagnosed I felt these were things I could control. My doctor says I am the healthiest MS and Cancer patient she has seen. No one would know I have either. I also do mindfulness meditation. I am the hapiest I have ever been and I am not Miss Sunshine.