Abstract: TH-PO1091

Hidden Sources of Sodium: The Role of Water Purification and Hypernatriuria in Kidney Stone Formation

Session Information

Category: Mineral Disease

  • 1204 Mineral Disease: Nephrolithiasis


  • Sodeinde, Adedeji Oluwatosin, Cleveland Clinic Foundation, Cleveland, Ohio, Beachwood, Ohio, United States
  • Brahmbhatt, Samir A., Cleveland Clinic Foundation, Cleveland, Ohio, Beachwood, Ohio, United States
  • Calle, Juan C., Cleveland Clinic Foundation, Cleveland, Ohio, Beachwood, Ohio, United States

One of the mainstays of dietary modification for prevention of calcium-containing stone formation is salt intake restriction. This is usually achieved by reducing dietary intake of high salt containing foods like smoked, cured or salted foods and canned goods. However the purity of water consumed is usually not addressed. The case presented here highlights the difference of well water, which is purified by reverse osmosis, compared to bottled water, which is purified by distillation, and their effect on urinary sodium levels.


A 49 year old male with a history that is significant for recurrent urinary tract infections due to uric acid and calcium oxalate stones was being followed up in the outpatient setting for stone prevention. Initial 24-hour urine studies were positive for hypercalcemia, hyperphosphatemia and hypernatruria, all while consuming well water purified by reverse osmosis. He was advised to drink and cook with bottled water which is purified by distillation. After the change, his initial urine sodium of 305 mmol/d decreased to 208 mmol/d. As a confirmation, it increased to 241 mmol/d when he asked to use well water again and back down to 177 mmol/d once back on bottled water.


As sodium restriction is one of the main therapies in preventing calcium-containing stones, there should be increased awareness about the routes with which it can be consumed. Reverse osmosis, though an efficient and economical method of water purification, may leave more sodium content in the water than distillation which is the purest form of water purification. If hypernatriuria remains an issue in a patient with persistent stone formation and well controlled dietary sodium ingestion, there might be benefits to assessing the water consumed and its purification process.