Sodium is neither a risk nor a protective factor in urolithiasis?

The effect of changes in urinary sodium, induced by dietary manipulation in normal subjects (NS) and in stone formers (SF) was studied by observing crytalluria qualitatively and by determining calcium, oxalate and phosphate crystallization quantitatively in an experimental model. In SF the calcium crystallization was significantly higher than in NS at all the three levels of urinary sodium studied. However, no difference was observed in oxalate and phosphate crystallization rates between these two groups.