Supplementing helps, but you may need to be more specific in your supplementing. Calcium actually inhibits the absorption of magnesium, so while you're getting your calcium, you may not be absorbing enough magnesium from other sources. I take my mag throughout the day, but my calcium only at night. I've noticed a HUGE difference and have "cured" several neurological problems I'd been having for years (particularly bladder irritability and frequency!!! And this problem started in my 20's so it wasn't age related). Also, Magnesium absorption is dose dependent - the more you take at one time the less you absorb. In a typical 400mg supplement, almost none will be absorbed. If you're really having issues with magnesium you can use a powdered or liquid form and add it to your food or drink during the day. I can only tolerate about 50-100 mg without nausea, so when I start getting symptoms of deficiency I add it back to my diet.

Calcium, magnesium, potassium and sodium are all essential for nerve conduction. If you don't have the right balance of each readily available then you can have all kinds of odd symptoms, muscle cramping being one. You can also have heart palpitations (a problem for me in the summer), and nerve pain (my brachialplexitis flares up when I'm getting low - a good sign for me that I need to supplement!). I also get headaches more easily and find that upping my cal and mag will make them go away pretty quickly. But the biggest thing for me is not getting up from 3-8 times a night to piddle (that is, just pee a little, though I have enough pain as if I have a full bladder). It is amazing how important the minerals are!

MNS