Nutritional aspects of urolithiasis.

Although there is much concern about the relationship between vitamin C consumption and oxalate or uric acid lithiasis in the urinary tract, there is no controlled clinical study that demonstrates this occurrence. Equal concern should be accorded the other nutritional links to urinary lithiasis, since it is very unlikely that vitamin C or any one of the other factors is ever the sole cause of a kidney stone. The rare persons who, because of an altered metabolism, convert much of the ingested vitamin C into oxalic acid constitute the only high-risk category. If the other known nutritional variables were also investigated in these metabolically crippled persons, it might be possible to reduce or eliminate their risk from the intake of vitamin C.