I was reading the post on Sensitive Stomach and supplements...and here I am looking and reading everything on the web about a problem that I was having...and here it is ....right on this message board!!!....I have tried (Calm) magnesium...Alka-mine Coral Calcium... and Barefoots Coral Calcium.(not all together..just kept switching to different brands because of the stomach..). I took these mainly for my Fibro...and yes it had made me hurting much better..however..I was experiencing heartburn...pain..and shortness of breath...along with (just reciently) raceing heart...thats when I just went off everything..and it seems to be inproving (my stomach)..I had no idea that this was what was making me feel like I coulden't breath..didn't have a clue..thought that it( Calcium/Mag )would help...if I had a problem with my stomach...but now that I have read these posts I see that this was probibly my problem all along...now I will probibly get back all my pain...but you know this all started after I had this long bout with the flu..and was put on Antibiotics...evertime I go on antibiotic..I end up with some kind of stomach problems...last time I thought I was having a Gall Bladder Or heart attack ...went in for all those wonderful tests...and it was fine...now what do I do??? because the coral calcium really did seem to help out with my pain....?? Anyway...just wanted to thank you for this message board...it has been so helpful for me...not with just the Fibro...but for a lot of other things, as well,,....Jeanne PS. Just last week went on UDO's probotics...thought my stomach was going to fall out of me...with the gnawing pain...!!!Stopped that too...!!!