Any dietary or drug treatment with high doses of micronutrients may override the body's own control mechanisms; therefore, micronutrient therapies may be associated with potential side effects and toxicities. High-dosed micronutrients should not be used without medical supervision.
A number of studies indicate that groups with relatively high dietary potassium intakes have lower blood pressures than comparable groups with relatively low potassium intakes (21).
Data on more than 17,000 adults who participated in the Third National Health and Nutrition Examination Survey (NHANES III) indicated that higher dietary potassium intakes were associated with significantly lower blood pressures (22).
In the Dietary Approaches to Stop Hypertension (DASH) trial, consumption of a diet including 8.5 servings/day of fruits and vegetables and 4,100 mg/day of potassium lowered blood pressure by an average of 2.8/1.1 mm Hg (systolic/diastolic blood pressure) in people with normal blood pressure and by an average of 7.2/2.8 mm Hg in people with hypertension, compared to a control diet providing only 3.5 servings/day of fruits and vegetables and 1,700 mg/day of potassium (23).
A meta-analysis of 33 randomized controlled trials including 2,609 individuals showed that increased potassium chloride (KCl) supplement intake (2,300–3,900 mg/day) resulted in slight but significant blood pressure reductions that averaged 1.8/1.0 mm Hg in people with normal blood pressure and 4.4/2.5 mm Hg in people with hypertension. Subgroup analysis indicated that the blood pressure-lowering effect of potassium was more pronounced in individuals with higher salt intakes and in trials where black individuals were a majority of the participants.