Medical researchers at the University of Alberta have found that people who eat high-sodium diets are prone to developing kidney problems and calcium depletion. The body gets rid of high levels of sodium via urinating, taking calcium with it. While high levels of calcium in urine can lead to kidney stones, low levels of calcium can lead to osteoporosis. The study reinforces the importance of a low-sodium diet and encourages paying careful attention to sodium levels in processed foods.
Health Canada: Sodium in Canada http://www.hc-sc.gc.ca/fn- an/nutrition/sodium/index-
The Kidney Foundation of Canada: Diets high in salt deplete calcium in the body