“Low potassium intake has been associated with a number of non-communicable diseases, including hypertension, cardiovascular disease, chronic kidney stone formation and low bone-mineral density. An increased potassium intake may reduce blood pressure, decrease risk of cardiovascular disease, have beneficial effects on bone-mineral density, and mitigate the negative consequences of high sodium consumption.”
The Linus Pauling Institute says fruits and vegetables are the best sources of potassium. Beans are also good. WHO recommends similar natural sources, and against simple supplementation.