heya, so it looks like your diet may not be keeping up with the d3 high dosing. it's very possible that your high d3 intake has depleted your magnesium status resulting in at least some of your symptoms. it happened to me :S no fun!
it is extremely important to get the recommended daily amount of dietary magnesium at an absolute minimum, if you are high dosing d3.
you can calculate your own daily magnesium intake using this chart (scroll down a little from this link):http://www.whfoods.com/genpage.php?tnam ... oodsources
note the only 'excellent' sources listed are spinach and swiss chard. you need a total of 4 c of these greens, boiled for 3 min, each day to meet the daily requirement. halibut appears to be the only significant seafood source (tuna a distant second). pumpkin seeds are rich in magnesium but also high in calories.
if you need a supplement, you can choose an organic (vs inorganic) soluble form, such as magnesium glycinate. avoid inorganic insoluble forms like magnesium oxide.
as for efficacy. if you can get a serum magnesium test done, it can tell you if your levels are adequate. fyi the 'normal' range is typically 0.70-1.10 mmol/L, way too wide for ms patients. so don't rest easy if you get a 'normal' result. you need to be in the top half of that range for sure, as per these studies looking at ideal levels:
Serum and Dietary Magnesium and the Risk for Type 2 Diabetes Mellitus (1999)http://www.ncbi.nlm.nih.gov/pubmed/10527292
"...Compared with individuals with serum magnesium levels of 0.95 mmol/L (1.90 mEq/L) or greater, the adjusted relative odds of incident type 2 diabetes rose progressively across the following lower magnesium categories: 1.13 (95% CI, 0.79-1.61), 1.20 (95% CI, 0.86-1.68), 1.11 (95% CI, 0.80-1.56), 1.24 (95% CI, 0.86-1.78), and 1.76 (95% CI, 1.18-2.61) (for trend, P=.01)"
translation: keep your levels above 0.95 mmol/L
About the Misdiagnosis of Magnesium Deficiency (2004)http://www.jacn.org/content/23/6/730S.full
"In patients with Mg serum values lower than 0.9 mmol/l Mg, magnesium supplementation is recommended; for patients with values lower than 0.8 mmol/l, starting Mg supplementation is necessary. We recommend that a mMg serum value of 0.9 mmol/l Mg be considered as the lower reference limit, in evaluating symptoms or diseases suspected as being associated with Mg deficiency. In this case, Mg has to be used as a first choice therapy."
translation: minimum level 0.90 mmol/L
Dose evaluation for long term magnesium treatment in aneurysmal subarachnoid hemorrhage (2005)http://www.ncbi.nlm.nih.gov/pubmed/16164489
"The mean serum magnesium level of 1.47 mmol/l was close to the proposed optimal serum magnesium level of 1.4 mmol/l for achieving maximal neuroprotection as demonstrated by Miles et al. In only a few patients serum magnesium concentrations exceeded the upper level of 2.0 mmol/l. It is suggested that above this level the neuroprotective properties of magnesium start to decline. This would implicate that studies aiming serum magnesium levels above 2.0 mmol/l are at risk to be less effective."
translation: levels above 1.4 mmol/L!
that's way higher than the status quo 'normal' range - some other authors replied to this but i can't see what they said (not free, boo!)
hope that helps!