whoooops i missed this earlier.
take some magnesium at the same time as D3, and some magnesium separately away from the D3.
i usually would recommend magnesium at bedtime, if it's a citrate form.
with magnesium glycinate i have trouble taking that at bedtime, it gives me a reflux cough.
yes magnesium and calcium compete with each other for absorption.
i haven't seen anything to suggest that ms patients are low in calcium, but i have seen studies showing low magnesium in ms patients.
ms patients might do better with a 2 parts magnesium to 1 part calcium blend.
my approach: no meds so far - just nutrient-dense anti-inflammatory whole foods, and supplements where needed
info: www.whfoods.com, www.nutritiondata.com