Potassium deficiency: causes, symptoms, consequences and how to treat it

Put simply, electrolytes such as potassium are minerals with an electrical charge. This potential difference between the cell and the extracellular space is crucial for ensuring that the metabolic processes in your body run smoothly. Most of the potassium is found inside your body’s cells and muscle cells, whilst some is also present in the liver, bones and red blood cells.

Potassium is a real all-rounder – and is therefore one of the most important electrolytes. Your body needs it for a range of functions:

• Energy metabolism: Potassium plays a major role in protein and carbohydrate metabolism – and therefore also ensures that cells grow.

• Fluid balance: This electrolyte regulates your body’s fluid balance and protects your cells from dehydration.

• Acid-base balance: This mineral helps to maintain your acid-base balance and ensure a healthy pH level.

• Heart and muscle function: Your body relies on potassium to transmit nerve impulses effectively and to enable muscles to contract.

• Blood pressure: This electrolyte is important for regulating blood pressure.

• Nerve health: Without this mineral, excited nerve cells cannot return to a resting state – so potassium also strengthens your nerves.

The bad news: your body cannot produce potassium itself, just like all other minerals. However: as a rule, a balanced diet provides sufficient potassium. Nevertheless, a potassium deficiency can occur in some cases. The most common causes include:

• Heavy sweating

• Intense physical exertion

• Insufficient fluid intake (particularly in older people)

• Taking diuretic medication

• Taking laxatives

• Conditions involving prolonged diarrhoea and vomiting

• Hormonal imbalances

• Eating disorders such as anorexia and malnutrition

• Heart conditions

• Kidney disorders

• Alcohol abuse

• Diabetes mellitus

A value between 3.6 and 5.4 millimoles of potassium per litre of blood is considered normal. A mild potassium deficiency is diagnosed when the concentration falls below 3.2 millimoles per litre. If your potassium level is too low, this may manifest itself through a number of symptoms. The problem is that many of these symptoms are non-specific and may also indicate other conditions. If you suspect a deficiency, you should therefore see a doctor and have a blood test carried out.

The following symptoms may indicate a potassium deficiency:

• Muscles that tire quickly and feel weak

• Difficulty concentrating

• Nervousness

• Loss of appetite

• Reduced bowel function with constipation

• Abdominal pain

• Headaches

• Dizziness

• Dry skin with an increased tendency towards acne

• Impaired wound healing

• Heart dysfunction

• Sleep disturbances

• High blood pressure

• Acidification of the body

As these symptoms are very non-specific, if you suspect a deficiency, you should consult your trusted doctor to have a blood test carried out.

A short-term potassium deficiency can usually be rectified quickly. However, if your body has to cope with too little potassium over a longer period of time, this can lead to serious consequences. A level of less than 3.5 millimoles per litre is considered a cause for concern, whilst levels below 2.5 millimoles per litre are regarded as a medical emergency. The heart, your muscles and the gastrointestinal tract are particularly affected. In emergencies, doctors therefore administer medication or intravenous fluids containing potassium.

The German Nutrition Society recommends approximately 4,000 mg of potassium per day for adults and adolescents. However, various conditions such as high blood pressure or other risk factors may mean that you need more than this. If you have certain pre-existing conditions, particularly kidney problems, you should only take potassium supplements after consulting a doctor.

A balanced diet is key when dealing with a potassium deficiency and can also help prevent it. Good sources of potassium include:

• Pulses

• Potatoes

• Cereal products

• Vegetables (particularly kale, broccoli, avocados, carrots and spinach)

• Mushrooms

• Fruit (particularly bananas, apricots, honeydew melon and berries) and dried fruit

• Fish (particularly trout and pollock)

• Nuts (particularly hazelnuts, cashews, peanuts and almonds)

• Dairy products

• Oatmeal

• Dark chocolate with a high cocoa content (enjoyed in moderation)

In addition, dietary supplements can help meet your requirements.

Potassium is often overlooked. Other, better-known minerals, such as magnesium or calcium, tend to take centre stage. Yet potassium is also essential for survival – your whole body benefits from an adequate intake, from your heart and nerves right through to your digestive system. You should therefore ensure you have a balanced diet that contains sufficient potassium. If necessary, you can take dietary supplements to complement your diet.