Urinary calcium/creatinin ratio with different dosages of vitamin D3 prophylaxis in infants

The requirement of vitamin D for breast-fed term infants remains an area of controversy. Different dosage is needed according to environmental factors such as sunlight exposure. Reception of more than 400 I.U. of vitamin D daily produces hypercalcemia. A random urine calcium/creatinin ratio [UCa/Cr] is a screening test for detection of hypercalciuria. Setting adequate values of vitamin D3 prophylaxis by random UCa/Cr in infant population of Yazd city in Iran, is the aim of present study. A total of 90 healthy, full term newborns of both genders were enrolled in the study. They were divided equally into three receiving vitamin D3 prophylaxis groups as follow: [I] 200 IU/daily, [II] 400 IU/daily and [III] 50000 IU two times in fifteen and sixty days after birth. A random urine specimen from each subject was analyzed for calcium, creatinin and serum 25-hydroxy-vitamin D at the end of three months of life. From all 90 studied infants, 25 [83.3%] infants with 200 IU/daily vitamin D3, 23 [76.7%] infants with 400 IU/daily vitamin D3 and 28 [93.3%] who received 50000 IU two times [76 infants, 84.4%] had hypercalciuria and 14 [15.6%] infants remained with low values of Ca/Cr ratios. According to high prevalence of hypercalciuria in this survey, it is recommended to evaluate the vitamin D level in infants and use proper amount of supplemented vitamin D. It seems that 200 IU/daily could be used in infants in our area