normal calcium, sodium and potassium to creatinine ratio in babol healthy adolescents

background: due to difficulty of obtaining a 24h urine (especially in children), a random urine calcium sample is recommended to detect of hypercalciuria. however, recent studies have shown that the urinary calcium/creatinine ratio varies with age and geographic areas. so, the aim of this study was determining the normal value of urinary calcium to creatinine ratio in healthy adolescent’s children. methods: four hundred eight children of 12 to 14-year-old were randomly selected from middle school in babol (north of iran) and early morning urinary samples of them were studied for determining normal urine ca/cr, na/cr and k/cr ratios. children who had the family with the history of renal disease were excluded from this study. results: in this study the 50% and 95% of urinary ca/cr ratio were 0.08±0.02 and 0.13 mg/mg for the whole group. the mean of urinary ca/cr ratio in boys and girls were 0.08±0.03 and 0.08±0.02, respectively. the mean of urinary na/cr ratio in boys was 1.4±0.48 and in girls was 1.21±0.33. also, the mean of urinary k/cr ratio in boys and girls were 0.30±0.11 and 0.29±0.10, respectively. conclusions: this study was shown that the urinary ca/cr ratio of these children is different from other geographic areas. also, a direct relationship was seen between urinary ca/cr ratio, na/cr and k/cr ratios.