The influence of a low protein diet in idiopathic hypercalciuria.

A group of 42 hypercalciuric patients (24 males and 18 females) aged 23 to 61 years (mean 45.57+/-12.27) with recurrent stone disease was studied. We applied for a period of 10 days a normocalcium, moderately low protein diet. We found statistically significant variations of azotaemia, venous pH, and vitamin D 1-25. In the 24 h urine collection we found a statistically significant decrease of nitrogen, uric acid, sodium, chloride, calcium, phosphates, oxalate, and hydroxyproline. In conclusion, the present study suggests that the restricted consumption of animal protein can produce a limited effect in urinary biochemistry. The actual efficiency of this dietary restriction on stone formation remains to be evaluated by a prospective long-term study of a larger population. Whether this has an effect on the future incidence of stone formation has to be further verified.