Compare to slow-mag the magnesium supplement that provides: magnesium chloride for increased absorption versus magnesium oxide enteric coating to help prevent stomach upset 226 mg of calcium per 2 tablet serving according to a usda agricultural research report, 7 out of 10 Americans are below the dietary reference intake for magnesium. Proper magnesium levels are required to help maintain: good cardiovascular health normal heart rhythms proper muscle function these statements have not been evaluated by the food and drug administration. This product is not intended to diagnose, treat, cure or prevent any disease. As a dietary supplement, take 2 tablets once or twice a day or as directed by your physician.