Association of death from renal failure with calcium levels in drinking water

The possible association between the risk of death from renal failure (RF) and the levels of calcium in drinking water from municipal supplies was investigated in a matched case-control study in Taiwan. Characteristics for all eligible RF-related deaths (2469 cases) among Taiwan residents from 1991 through 2000 were compared with those of people who died from other causes (2469 controls). The levels of calcium in the drinking water of these residents were determined from data obtained from the Taiwan Water Supply Corporation (TWSC). The controls were pair-matched to the RF-related cases by year of birth and death. The adjusted odds ratios (ORs) (95% confidence interval, CI) for RF-related deaths were 1.21 (1.03-1.43) for the group with water calcium levels between 25.1 and 43.0 mg/L and 1.34 (1.12-1.60) for the group with calcium levels of 43.3 mg/L or more. There was a significant trend for increased risk of death from RF with higher calcium levels in drinking water.