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Potassium and your health
9-minute read
Key facts
- Potassium is a mineral that is essential for all your body's functions.
- It helps your nerves, muscles and heart to work and it also helps move nutrients to your body's cells.
- Most people get enough potassium from their diet.
- Both high and low levels of potassium in the body can be dangerous.
What is potassium?
Potassium is a mineral that is essential for your body.
Why is potassium important for my health?
Potassium has many important functions:
- It allows your nerves to respond to stimulation and your muscles to contract (tighten), including those in your heart.
- It reduces the effect of sodium (present in table salt) on blood pressure.
- It helps move nutrients into cells, and waste products out of cells.
Having the right amount of potassium helps:
- control blood pressure
- protect against strokes and cardiovascular disease
- protect against osteoporosis
- prevent kidney stones
Your kidneys control potassium levels in your body and get rid of excess potassium in urine (wee).
If your kidneys do not work properly, potassium may build up in your blood. This can be very dangerous — it may cause your heart to beat irregularly or stop beating (cardiac arrest).
Where does potassium come from?
Potassium comes from your diet. Some foods are especially high in potassium, such as:
- reduced-salt packaged foods
- coffee, chocolate, liquorice
- salt substitutes
- fruit juices, and milkshakes
- leafy green vegetables
- starchy vegetables
- dried fruits and tropical fruits
You can read more about foods high in potassium.
You can also get potassium from vitamin supplements.
How much potassium do I need?
Most healthy people get enough potassium through their diet.
How much potassium you need depends on:
- your sex
- your age and life stage
- whether you have any medical conditions
| Stage of Life | Recommended dietary intake* of potassium (milligrams per day) |
|---|---|
| 0-6 months | 400 |
| 7-12 months | 700 |
| 1-3 years | 2,000 |
| 4-8 years | 2,300 |
| 9-13 years males | 3,000 |
| 9-13 years females | 2,500 |
| 14-18 years males | 3,600 |
| 14-18 years females | 2,600 |
| Adult males | 3,800 |
| Adult females | 2,800 |
| During pregnancy | 2,800 |
| While breastfeeding | 3,200 |
*Recommended dietary intake (RDI): is the average daily dietary intake level that is needed to meet the nutrient requirements of nearly all (97–98%) healthy individuals in a certain life stage and gender group.
Babies under 12 months can get all the potassium they need from breast milk, formula and food.
The amount of potassium your body needs is affected by:
- the climate
- your level of physical activity
- using diuretic medicines (medicines that make you produce more urine)
- how much sodium you eat (linked to how much table salt you use in food)
- your kidney function
An imbalance of potassium can lead to health problems.
Because having too much potassium can affect your health, only take a potassium supplement if your doctor prescribes one.
Can I have too little potassium?
Low potassium (hypokalaemia) can lead to symptoms including:
- weakness and fatigue
- muscle cramps
- constipation
- abnormal heart rhythms (arrhythmias)
It can also lead to metabolic acidosis, which can affect your bones.
There are many causes of hypokalaemia. Common causes include taking diuretic medicines and dehydration that may happen due to:
Hypokalaemia is not common. Occasionally, people may have low potassium because they don't eat enough foods that are high in potassium.
Read more on potassium deficiency.
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Can I have too much potassium?
If you think you or someone else is having a cardiac arrest, call triple zero (000) immediately and ask for an ambulance. In the meantime, start CPR and follow all instructions given by the triple zero (000) operator.
High potassium (hyperkalaemia) is a serious and potentially life-threatening condition.
Hyperkalaemia has many possible causes. Most commonly, it is caused by kidney disease or taking medicines that lower the amount of potassium your kidneys remove from the body.
Potassium is also an ingredient used in some salt substitutes — talk to your doctor before using these.
If you have a higher chance of hyperkalaemia, you may need to limit the amount of potassium in your diet.
Hyperkalaemia can cause problems with your digestive system and cardiovascular system.
If you have unusually high levels of potassium, you may:
- feel weak and tired
- breathe slowly (hypoventilate)
- feel nauseous (feel sick)
- vomit
- have abdominal (tummy) pain
- have an abnormal heart rhythm
- have a cardiac arrest
If you have heart palpitations, seek urgent medical advice. This can be a sign of an irregular heartbeat (arrhythmia), which can lead to cardiac arrest.
If you have these symptoms and believe your potassium levels might be high, call your doctor immediately. They can check your potassium levels with a blood test.
Your doctor might discover you have high potassium through blood tests you had to explain or monitor another condition.
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Resources and support
Eat for Health uses the Australian dietary guidelines to provide advice about the amount and types of food you need. This includes information on how much potassium you need.
If you have kidney disease, learn how much potassium to include in your diet by visiting Kidney Health Australia.
You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with 24 hours a day, 7 days a week.