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Potassium supplements |
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Potassium is an essential mineral needed to regulate water balance, levels of acidity and blood pressure. Potassium is a mineral that is involved in both electrical and cellular functions in the body. In the body it is classified as an electrolyte. Electrolytes are substances such as sodium, potassium or chloride that are used by cells in the body to regulate electric charge and flow of water molecules across a cell membrane. Potassium is the principal positively charged ion (cation) in the fluid inside of cells, while sodium is the principal cation in the fluid outside of cells. It is one of the substances found in foods that maintain the body's internal balance of fluids and chemicals. The kidneys and heart also work to keep the balance. Potassium is the principal intracellular cation, with a concentration of about 145 mEq/L, as compared with a normal value of about 4 mEq/L in extracellular fluid, including blood. More than 98% of the body's potassium is intracellular; measuring it from a blood sample is relatively insensitive, with small fluctuations in the blood corresponding to very large changes in the total bodily reservoir of potassium. Potassium's role is to maintain water balance inside the cells and help in the transmission of nerve impulses. Low or high levels in the blood are of critical significance. Potassium helps to maintain proper muscle and nerve function; it also helps in some important metabolic processes. Blood serum potassium levels usually are determined to help evaluate heart rhythm irregularities, neuromuscular disorders and kidney function. A diet high in potassium from fruits, vegetables, and legumes is generally recommended for optimum heart health.
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Biological functions and health benefits of potassium |
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| Potassium is important in body functions such as regulation of blood pressure and of water content in cells, transmission of nerve impulses, digestion, muscle contraction, and heartbeat. It helps to maintain proper muscle and nerve function; it also helps in
some important metabolic processes. Potassium regulates the water balance and acid-base balance in the blood and tissues. Blood serum potassium levels usually are determined to help evaluate heart rhythm irregularities, neuromuscular disorders and kidney function.
Potassium works with sodium to maintain the body's water balance. Potassium and sodium are the two cations mainly responsible for the osmotic pressures of intracellular and extracellular fluid (ICF and ECF, respectively). Sodium, found primarily in ECF, is actively moved from ICF to ECF by sodium-potassium pumps in the cells. The ICF is the principal location of potassium, where it can not be clinically measured. The movement of potassium across the cell membrane is crucial to cardiac and neuromuscular excitability. Membrane potential is altered by changing the ratio of ICF potassium to ECF potassium. Potassium, together with sodium, helps to regulate the blood pressure and is important for the proper function of the heart and kidneys. Increasing potassium in the diet may protect against hypertension in people who are sensitive to high levels of sodium. Increased potassium may increase the amount of sodium excreted from the body. The osmotic gradient of potassium between intracellular and extracellular space is essential for nerve function; in particular, potassium is needed to repolarize the cell membrane to a resting state after an action potential has passed.
Potassium is also essential to the normal muscular function, in both voluntary muscle (e.g. the arms and hands) and involuntary muscle (e.g. the heart and intestines). Potassium assists in muscle contraction and in maintaining fluid and electrolyte balance in body cells. Potassium is also important in sending nerve impulses as well as releasing energy from protein, fat, and carbohydrates during metabolism. Severe abnormalities in potassium levels can seriously disrupt cardiac function, even to the point of causing cardiac arrest and death. |
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Potassium deficiency (hypokalemia) |
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| Lack of potassium may cause muscle weakness, irregular heartbeat, mood changes, or nausea and vomiting. A shortage of potassium can cause a potentially fatal condition known as hypokalemia. Symptoms of hypokalemia include weakness, lack of energy, muscle cramps, stomach disturbances, an irregular heartbeat, and an abnormal EKG (electrocardiogram). Potassium deficiency will increase acid levels in the body, lowering the natural pH, which will have far reaching effects. Lack of potassium can also aggravate problems caused by lack of protein. Potassium deficiency can cause problems with the formation of connective tissue, and can render normally strong body tissue vulnerable to all kinds of problems. A deficiency of potassium (hypokalemia) can occur in people with chronic disease or as a result of the aging process. The most common problems associated with reduced potassium levels are hypertension, congestive heart failure, cardiac arrhythmias, depression, and fatigue.
A variety of conditions can cause the loss of potassium from the body. The most common of these conditions are vomiting, diarrhea, and other gastrointestinal problems Kidney disease (such as acute renal failure) and diabetes, depending on the stage of either, can also cause fluctuations in the levels of potassium. Additionally, many medications can cause depletion of potassium. Examples include diuretics, cortisone, prolonged use of aspirin, and laxatives. The most common symptom of potassium depletion is fatigue. Other symptoms of potassium deficiency include slow reflexes, muscle weakness, and dry skin. A quick loss of potassium could lead to cardiac arrhythmias. Severe potassium deficiency symptoms include decreased heart rate, extreme muscle weakness, bone fragility and, if untreated, death. A low level of potassium can be determined with a blood test and can be treated with potassium supplements. |
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Dietary sources of potassium |
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The best dietary sources of potassium are fresh unprocessed foods. Fish such as salmon, cod, flounder, and sardines are good sources of potassium. Various other meats also contain potassium. Vegetables including broccoli, peas, lima beans, tomatoes, potatoes (especially their skins), and leafy green vegetables such as spinach, lettuce, and parsley contain potassium. Fruits that contain significant sources of potassium are citrus fruits, apples, bananas, and apricots. Dried apricots contain more potassium than fresh apricots. There are several potassium supplements on the market, including potassium acetate, potassium bicarbonate, potassium citrate, potassium chloride, and potassium gluconate.
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Dosage, intake, recommended daily allowance (RDA) |
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Because lack of potassium is rare, there is no recommended daily allowance for potassium. It is usually easy to obtain adequate potassium in a normal balanced diet. The range of actual intake for children is 780 to 1,600 mg per day; adults the range is 1600 to 2000 mg per day.
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Side effects, precautions, toxicity, and drug interactions |
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Gastrointestinal symptoms, including nausea, vomiting, abdominal discomfort, and diarrhea, are the most common side effects of potassium supplements. Other potential adverse effects include muscle weakness, slowed heart rate, and abnormal heart rhythm. Increased level of potassium in the blood is known as hyperkalemia. This may be related to increase in total body potassium or excessive release of potassium from the cells into the bloodstream. Hyperkalemia can have serious, potentially life-threatening effects on the body. People with kidney failure should not take potassium supplements.
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Potassium is a vital element for proper body function. As the most abundant mineral in the body, potassium is the key to proper kidney function as well as central in cardiac, skeletal and smooth muscle contraction. A deficiency in potassium is called hypokalemia and may result in serious conditions including arthritis, heart disease and high blood pressure. Click here for more information.