The Amazonian Yanomami Indians famously manage on only 50 mg (1 mmol) of sodium chloride per day, while in more developed societies, we struggle to keep our average intake below 100 times that level.
From about 1964, there was increasing excitement that dialysis might become a major life-saving treatment for chronic renal failure, not just for acute renal failure. Transplantation was also in its infancy, but despite some promise, overall success rates at this time were very poor.
Willem Kolff is famously the man who first put the developing theory of therapeutic dialysis into successful practice in the most unlikely circumstances: Kampen, in the occupied Netherlands during World War II. Influenced by a patient he had seen die in 1938, and in a remote hospital to avoid Nazi sympathisers put in charge in Groningen, he undertook experiments with cellulose tubing and chemicals and then went straight on to make a machine to treat patients from 1943.