just found the most interesting non profit site that gives mega info o how to choose which brand of coral calcium. The do not sell any they just tell you how and what to look for and they rate all the brands. Go to google and punch in coral calcium watch dog and that should get you there. It really helps you seperate they hype from the real data and since this product is expensive and not always full of the good stuff we need to be informed. I do not know who these people are and have not been able to determine if they are a phony front for the top brand but you can decide for yourself.