My nephrologist (kidney specialist) told me to drink 1/4 cup of fresh or reconstituted lemon juice ever day in order to prevent kidney stones. What he explained is that the most common form of kidney stone (calcium oxalate) can be prevented by this. The citrates in the lemon juice latch onto the very large di-calcium phosphate molecules that can sometimes get lodged in the kidney, and then safely and easily transport them out of kidney so that stones do not develop. This has worked for me!