Potassium is an essential mineral and electrolyte vital to the proper functioning of the body. All cells, tissues and organs require potassium. As an electrolyte, potassium has the ability to dissociate and form ions which conduct electricity. Potassium concentrations, both inside and outside of cells, are tightly controlled by mechanisms within the body. A potassium deficiency, or hypokalemia, may result from a variety of conditions. There are notable symptoms of low potassium regardless of the underlying cause.
Potassium plays many important roles in the body, both as an electrolyte and a mineral. As an electrolyte, potassium is responsible for carrying nerve impulses to your cells and conducting electricity. Potassium is involved in nerve function, smooth muscle contraction, normal digestion and heart function and regulation of blood pressure. Potassium works closely with sodium to maintain your body’s fluid balance. Potassium controls pH balance, proper growth and development, carbohydrate metabolism and protein synthesis. The kidneys regulate the amount of potassium in your body by controlling potassium excretion.
The Food and Nutrition Board of the Institute of Medicine established intake levels for potassium that have been proven to lower blood pressure, reduce salt sensitivity and minimize the risk of kidney stones. For individuals over the age of 14, potassium requirements are 4.7 g per day. Potassium needs increase to 5.1 g per day for breast-feeding women but do not change for pregnant women. Most Americans do not get enough potassium from the foods they eat.
Causes of Deficiency
You obtain potassium through food in your diet. When there is excess potassium, your kidneys remove it as part of the urine to maintain a proper electrolyte and mineral balance in your body. Hypokalemia is the metabolic condition that results when potassium levels in the blood fall below normal. The most common causes of hypokalemia include diarrhea, vomiting or other loss of body fluids; certain drugs, such as antibiotics and diuretics which increase urination; consuming foods rich in sodium; diseases that affect the kidney’s ability to retain potassium; eating disorders, such as anorexia and bulimia; sweating; and eating large amounts of licorice or using products that contain licorice made with glycyrrhetinic acid.
A small fluctuation of potassium does not typically cause symptoms. However, a marked drop can be life threatening. If you suffer from a potassium deficiency, you may experience abnormal heart rhythms, heart palpitations, constipation, breakdown of muscle fibers, muscle weakness, fatigue, lightheadedness and paralysis. Lightheadedness is characterized by feeling weak, unsteady, faint and even dizzy. Dizziness and lightheadedness may interrupt your ability to do certain activities, but it is rarely a serious or life-threatening condition.
Lightheadedness and Low Blood Pressure
The kidneys require potassium along with other electrolytes to maintain water balance in the body. If there is a limited amount of potassium due to a deficiency, the body will excrete excess water through the urine. When the body loses a significant amount of water, blood pressure can drop. In turn, low blood pressure may result in lightheadedness, dizziness and even fainting, especially upon standing.
Treatment for hypokalemia depends upon its cause and severity. Mild hypokalemia can be treated by consuming a potassium-rich diet or taking oral potassium supplements. More severe cases may require intravenous potassium. To prevent feelings of lightheadedness, consume foods such as fruits, vegetables, legumes, nuts, seeds and certain dairy products. Consult your doctor if you suspect you have a potassium deficiency.