Here is a good link about the need for taking magnesium with calcium:

http://www.mgwater.com/calmagab.shtml

Also all calcium is not thought to be equally beneficial. The following sources are associated with lead: oyster shell, dolomite and bone meal. I recall calcium citrate as being one form that is easier to absorb. My personal fav is fortified OJ and the Stonyfield Farm's yogurt drinks.

Quill

Quote Originally Posted by Grog
The recommended daily intake of calcium is 1200 mg a day, or so, for a woman.

Plus vit D (can't remember how much) for absorbtion.

A decent glass of milk is about 300 mg, to give you a ballpark measure.

However I've always thought cramps were caused by potassium and magnesium deficits, not to calcium.