Peg,

The brand I take is KAL Extra Strength Calcium-Magnesium. Here are the Supplement Facts:
Serving Size 2 tablets
Calcium (as Calcium Carbonate, Calcium Amino Acid Chelate) 1000 mg, % DV: 100
Magnesium (as Magnesium Oxide, Magnesium Amino Acid Chelate) 500 mg, %DV: 125
Betaine HCI 100 mg, %DV: not established.

I also take 396 mg of potassium gluconate, per Drs. Eades' recommendation in Protein Power LifePlan.

The bottoms of my feet used to cramp when I went to bed, now they don't.

HTH,