Definition Potassium is one of the electrolyte minerals. It is important in maintaining the body's acid-base and fluid balance. Potassium works very closely with sodium and chloride, which are also electrolyte minerals. These three minerals are in all fluids of the body. Potassium is found in fluids within cells. The other two are found in fluids outside of cells.
What food source is the nutrient found in? Potassium is abundant in the diet. It is found in most
fruits
vegetables
dairy products
fish
lean meats
grains
poultry
Bananas, potatoes, avocados, mushrooms and orange juice are especially good sources of potassium. Other good sources include apricots, nuts, and cooked or dried beans and peas.
How does the nutrient affect the body? Potassium is found inside the cells, where it works with sodium, on the outside of the cells, to keep fluids balanced correctly. Working with sodium, potassium assists in the smooth working of muscles, such as the heart. This role is critical to basic heart function and blood pressure. It also helps transmit nerve impulses or signals.
Information A deficiency of potassium in the diet is unlikely and generally rare. Potassium deficiency can occur because of vomiting, diarrhoea and long-term laxative and diuretic use. Low potassium levels can also be caused by chronic disease and the ageing process. Kidney problems can cause a severe imbalance of potassium. Common problems associated with low potassium levels include:
People taking medication for high blood pressure, such as diuretics, may need to take a potassium supplement. These individuals should consult their doctor.
The body protects itself from potassium toxicity by dissolving and excreting the mineral. In severe cases, a person will vomit, to keep blood levels within safe limits. When blood levels of potassium start to measurably rise it is called hyperkalaemia. This is usually due to a specific cause such as reduced kidney function, increased protein breakdown or severe infection. If excess potassium cannot be excreted, it can cause heart problems. People with kidney problems may not be able to excrete excess amounts. They may be put on a potassium-restricted diet. They need to be careful of salt-substitutes. Salt-substitutes are usually made of potassium chloride. Regular salt is made from sodium chloride.
The Recommended Dietary Intake (RDI) for potassium is a minimum amount of 50-140 mmol per day (1950-5460 mg) for adults. Some experts suggest a level of about 3,500 mg per day to help protect against high blood pressure. The typical Australian adult gets between 50-140 mmol (1950-5460 mg) per day or more. Following the Australian Guide To Healthy Eating should ensure a safe daily intake of potassium.
Author: Clare Armstrong, MS, RD Reviewer: eknowhow Medical Review Panel Editor: Dr John Hearne Last Updated: 17/11/2004 Contributors Potential conflict of interest information for reviewers available on request
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