Potassium supplementation does not lower blood pressure in normotensive women

Forty-four normotensive females, who were selected on the basis of lower prevailing potassium intake, participated in a two-period crossover study to assess the effects of potassium supplementation on blood pressure. They were randomly allocated to one of two groups who took either 80 mmol/day of KCl (Slow-K, Ciba Geigy), or matching placebo, for the first of two 4-week treatment periods. The treatments were reversed during the second 4-week period. Despite significant increases in both urinary and plasma potassium no consistent fall in blood pressure was seen during 80 mmol/day potassium intake.