true, not useless, the lease expensive option and certainly better than prilosec. Carbonate has more elemental calcium than citrate but less absorbed. Some on the forum may not know that when asking about calcium supplementation. I'm not arguing with you about taking it for GERD, just saying that it's not the best option to recommend specifically as a calcium supplement. (as an aside, I used to have GERD and by using diet and herbs, I know longer have it)