One has to take care when taking vitamins and minerals "alone". Calcium and magnesium need each other in a ratio that is very complicated and with all the foods and doctors, etc. emphasizing calcium but not paying adequate attention to magnesium, one gets "different" problems. "More" of something is not necessarily better. I would talk to my doctor.

http://www.magnesiumeducation.com/fi...tio-3-1-12.pdf