 Each subject will participate in all four phases, chosen in random order. The four phases will be: Placebo Phase microcrystalline cellulose in water, Potassium Chloride Phase potassium chloride powder in water, Potassium Citrate Phase potassium citrate powder in water, KMgCit Phase KMgCit powder in water During each phase, subjects will receive one of the test drugs for 4 weeks, followed by at least 1 week of withdrawal. Change in 24 hr BP, office BP will be measured at baseline and after each phase. Central aortic blood pressure and carotid-femoral pulse wave velocity, -terminal-telopeptide CTX, 24 hr urine electrolytes will be measured at 4 weeks in each phase. 