Potassium

Potassium helps the kidneys function normally. It also plays a key role in muscle contraction, making it an important nutrient for normal heart, digestive, and muscular function. A diet high in potassium from fruits, vegetables, and legumes is generally recommended for optimum heart health.
Having too much potassium in the blood is called hyperkalemia and having too little in the blood is known as hypokalemia. Proper balance of potassium in the body depends on sodium. Therefore, excessive use of sodium may deplete the body's stores of potassium. Other conditions that can cause potassium deficiency include diarrhoea, vomiting, excessive sweating, malnutrition, and use of diuretics including caffeine and alcohol. Adequate amounts of magnesium are also needed to maintain normal levels of potassium.
For most people, a healthy diet rich in vegetables and fruits provides all of the potassium needed. The elderly are at high risk for developing hyperkalemia due to decreased kidney function. Older people should be careful when taking medication that may further affect potassium levels in the body, such as nonsteroidal anti-inflammatories (NSAIDs) and ACE inhibitors but also many other drugs. Taking potassium supplements with medications, at any age, should only be done under the guidance of a healthcare provider.
Symptoms of potassium deficiency include weakness, lack of energy, muscle cramps, stomach disturbances, and an irregular heartbeat.
High dietary intake of potassium from fruits and vegetables throughout one's life helps to preserve bone mass thereby preventing osteoporosis.
Some studies have linked low dietary potassium intake with high blood pressure.
In several population-based studies on very large groups, a diet rich in potassium was associated with a reduced risk of stroke. For the men, this seems to be particularly true among those with high blood pressure and/or those taking diuretics (blood pressure medications that help the kidneys eliminate sodium and water from the body). Potassium supplements, however, do not seem to reduce the risk of stroke.
Amongst other nutrient deficiencies, people with IBD (ulcerative colitis or Crohn's disease) often have low levels of potassium, probably because of malabsorption. Your doctor may suggest potassium supplementation, along with some others, if you have any of these problems.
Several studies have suggested that diets low in potassium are associated with poor lung function and even asthma in children. Enhancing dietary intake of potassium may, therefore, prove to be of value for preventing or treating asthma.
The best dietary sources of potassium are fresh unprocessed foods, including meats, fish, vegetables (especially potatoes), fruits (especially avocados, dried apricots, and bananas), citrus juices (such as orange juice), dairy products, and whole grains. Most potassium needs can be met by eating a varied diet with adequate intake of milk, meats, cereals, vegetables, and fruits.
There are several potassium supplements on the market, including potassium acetate, potassium bicarbonate, potassium citrate, potassium chloride, and potassium gluconate. Unlike the case of most other minerals, the absorbability of these does not vary greatly, but chelated potassium is probably the best absorbed. Potassium can also be found in some multivitamins.
Diarrhoea and nausea are two common side effects from potassium supplements. Other potential adverse effects include muscle weakness, slowed heart rate, and abnormal heart rhythm.
Excessive amounts of the herb liquorice (not liquorice sweets) and caffeine-containing herbs (such as cola nut, guarana, and possibly green and black tea) can lead to loss of potassium.
Potassium must not be used by people with hyperkalemia.