Potassium and Sodium work together to maintain proper fluid balance and regulate the contraction of muscles and transmission of nerve impulses. Potassium also helps maintain blood pressure. Eating a diet high in potassium helps maintain a lower blood pressure.
The AI for potassium is 4.7 g/day for men and women aged 19 to 50. It is found in many fresh foods, mostly fruits and vegetables. Foods that are processed are usually loaded with sodium and decreases the amount of potassium. People with kidney disease aren’t able to regulate their blood potassium levels. Hyperkalemia or high blood potassium concentration, occurs when potassium is not efficiently excreted from the body. Severe hyperkalemia can alter the normal rhythm of the heart which can result in a heart attack or death. People with kidney disease must monitor their potassium intake.
Potassium is widespread in many foods so a deficiency is rare. Potassium deficiency is not uncommon among people who have serious medical disorders however. Kidney disease, diabetic ketoacidosis, and other illnesses all can lead to a potassium deficiency. People with high blood pressure who are prescribed diuretic medications to treat their disease are also at risk. Some diuretics can increase the body’s urinary excretion of potassium. Extreme dehydration, vomiting and diarrhea can cause hypokalemia, which is low blood potassium. People who abuse alcohol or laxatives can suffer from this. Severe cases result in fatal changes in heart rate. Many deaths attributed to extreme dehydration or eating disorder are caused by abnormal heart rhythms due to hypokalemia.
Source: Thompson, Janice, Melinda Manore, and Linda A. Vaughan. The Science of Nutrition. San Francisco, CA: Pearson Benjamin Cummings, 2011. Print.