Hi Lisa, I don't have MS as you probably are aware. However, I do take a lot of Vit D3. I also have some similar symptoms with my legs. So I wanted to share my experience with you -- hope it is helpful.   I take 10,000 IU of Vit D3 daily (1 casule of 5000 IU morning and evening). This has defiantely made a difference in my low energy levels. Although taht is not your complaint, I just wanted to share that I have to take a very high dosage to see therapeutic benefit and that is not uncommon. I mention it fo ryour consideration.   As far as my legs, long story of tingling, pain, and numbness for a few years and docs being unable to resolve. We finally were going to try pain injections in the spine, quite a controversial procedure. As luck would have it, my employer switched insurance providers and my physician did not participate in the new insurance. During the time that I was waiting for an appt with a participating specialist, I had begin using magnesium citrate powder. After a month, I had no more of the synptoms with my legs.   I began using the magnesium citrate powder for constipation, totally unrelated to the leg problems. But it resolved all the issues with my legs. If I stop taking it, the pain, tinglinging, numbeness returns. I never have gone for those pain injections.   Someone in the healthcare field had told me that researchers have found a magnesium deficiency in RLS restless leg syndrome sufferers. Although I was ruled out for RLS, the magnesium citrate worked wonders. Ergo, there must be some correlation.   Perhaps worth considering a try. I recommend the powder in a glass of water, not the pills/capsule.   I hope that this helps. MBL