normal value of random urinary calcium to creatinine ratio in children in zahedan, south-east of iran

Background: random urine calcium/creatinine ratio (uca/cr) is used practically for the screening of hypercalciuria. objectives: this study aimed to determine the age-specific reference value of uca/cr and its relationship with urinary na/k in children in zahedan, south-east of iran. methods: in a cross-sectional study, uca/cr and una/k ratios were measured in non-fasting morning urine samples of 1,506 randomly selected primary school children.results: the prevalence of hypercalciuria was 3.1%, with no significant difference between males and females. mean uca/cr was 0.09 0.21, and the 95th percentile was 0.27 and 0.22 in seven and 12-year-old children, respectively. mean urinary una/uk was 2.901.89, and the 95^th percentile was 7.83 and 10.57 in seven and 12-year-old children, respectively. the correlation between uca/cr and una/uk wasstatistically significant (r=0.128, p< 0.001). therewasalso a positive correlation between uca/cranduna/uk, especially in sevenyear- old children (r=0.508, p < 0.001). conclusions: different reference values of uca/cr for seven and 12-years-old emphasize that age-specific reference values of uca/cr should be established for each population to be used as a screening method for hypercalciuria.