Randomised double-blind cross-over trial of potassium on blood-pressure in normal subjects.

A randomised double-blind cross-over study of increased oral potassium 64 mmol a day versus placebo was conducted in 20 young healthy males on normal sodium unrestricted diet. A significantly greater proportion had lower systolic and diastolic blood-pressures on potassium than on placebo. The mean diastolic pressure was significantly lowered, by 2.4 mm Hg, during potassium supplementation. Change in diastolic pressure correlated negatively with change in 24-hour urinary potassium and positively which change in 24-hour urinary sodium/potassium ratio in individual subjects.