Shafiee MA, et al. - Herein, the risk of calcium phosphate (CaHPO4) precipitation after 18 hours of food and water deprivation was measured by the experts. Findings suggested a statistically significant steady decrease in urine flow rate (UFR) during the 18 hours of food and water deprivation, however, there was not any evidence suggesting that the calculated risk of CaHPO4 precipitation in the healthy subjects had increased.