My mother has been told to take calcium supplements by her doctor. I believe they ran tests on her, including X-Rays and other pertinent tests to determine her bone density and other factors, which led to the conclusion she should supplement calcium, magnesium, and Vitamin D. She has a Mg/Vit D supplement, but I was wondering what kind of calcium supplement is best in these situations. I've read some articles (not journals) suggesting slow-release calcium supplements are better as too much calcium intake in a sitting is somewhat useless and can't be absorbed at the same time. Is this true? Also, what form of calcium would be best (is calcium carbonate just as well as calcium citrate, for instance)?