Serum zinc, copper and manganese levels were estimated in normal subjects (NS) and stone formers (SF). There was no significant difference in the serum levels of Zn, Cu, and Mn in NS and SF, the values being 101.5±35.1 μg% and 94.3±45.6 for Zn; 91.75±27.0 μg% and 88.5±34.1 for Cu; and 87.0±36.7 μg% and 79.6±35.5 for Mn, respectively. Zinc excretion was relatively high in NS (790.08±172.88 μg/dl) as compared to other populations and was significantly higher in SF (1154.92±290.17 μg%, p<0.001). Copper and manganese excretions in SF were significantly lower than in NS (p<0.001).

Zinc was present in substantial quantities in renal (2.52±3.98 g%), ureteric (0.75±0.51 g%) and vesical (1.71±3.20 g%) stones. Manganese was present in traces in all the stones and copper in two-thirds of the stones.