Coral, particularly in the form of "coral calcium," has a longstanding place in traditional healing systems, especially within some branches of Ayurveda and traditional Asian medicine. Coral is believed to possess cooling properties and is sometimes prescribed in these traditions for urinary tract health, which includes support for patients with kidney stones. The rationale is rooted in the mineral content of coral, chiefly calcium carbonate, which is thought to help balance bodily fluids and reduce "heat" or inflammation.

However, the scientific evidence supporting the use of coral or coral calcium for the treatment or prevention of kidney stones is minimal to nonexistent. In fact, increasing calcium intake through supplements can sometimes raise the risk of certain types of kidney stones, particularly in those predisposed to calcium oxalate stones. No clinical trials or rigorous studies have established coral's efficacy or safety in this context. The use persists mainly due to tradition and anecdotal reports rather than robust evidence.

In summary, while coral is used for kidney stones in some traditional medicine systems, its efficacy is not supported by scientific research, and there may even be risks associated with its use in this context.