Potassium supplementation in blacks with mild to moderate essential hypertension.

Potassium chloride (KCl) salt (65 mmol) daily reduced BP from 153/104 to 146/101 mmHg in 32 hypertensive black females during a 6-week placebo controlled crossover study. The fall in BP was independent of the order of randomization and was significant for systolic (SBP; P less than 0.01) and diastolic (DBP; P less than 0.05) pressure after 4 weeks. Analysis of the 95% confidence intervals in this and in five other studies, two of which were reported as showing no beneficial effect, suggests that potassium supplementation does lower BP, but that the change is small and within the confidence levels of all six trials. Thus, apparent discrepancies in the literature are not genuine statistically.