Potassium

Potassium is an essential mineral that plays a role in many biological functions, such as blood pressure regulation, nerve transmission and muscle contraction. Fruit, vegetables and certain dairy products are the main dietary sources of potassium.

Potassium: a key element for many physiological functions

Potassium is the main intracellular cation in the body. Together with sodium, it primarily plays a part in maintaining membrane potential . This mineral plays a crucial role in nerve transmission, muscle contraction and cardiac function. It is also needed for insulin secretion and the body’s acid-base balance (ANSES, 2021).

Nearly 90% of dietary potassium is absorbed in the small intestine. Potassium balance is regulated by the interaction between dietary intake and renal excretion, with urine being the main route of elimination (EFSA, 2016). Most of the body’s potassium is stored in the muscles, but it is also found in the bones, liver, skin and red blood cells.

Potassium: needs that change throughout life and differ according to gender

Potassium needs increase throughout childhood and into adulthood. ANSES and EFSA consider that there is no suitable biomarker of potassium status (EFSA, 2016). However, it has been established that an intake of 3500 mg/d has a beneficial effect on blood pressure in adults, and that an intake below this threshold increases the risk of stroke.

The data currently available are insufficient for determining an average requirement (AR) for potassium but can be used to define an adequate intake (AI) (see Table 1 below).

Table 1: Adequate potassium intake (mg/d)

Potassium, a variety of food sources

Potassium is mainly found in fruit, vegetables, chocolate and dairy products (ANSES, 2019). Fruit and vegetables (excluding fruit juices) account for around 23% of potassium intake in adults (ANSES, 2017).

Potassium deficiencies and excesses: their impact on health

A potassium deficiency can cause muscle cramps, severe fatigue and heart rhythm disorders (ANSES, 2019). Nevertheless, daily needs can generally be met through a varied and balanced diet.

Hypokalaemia – a blood potassium level below 3.5 mmol/L – may result from excessive losses (diarrhoea, vomiting) or from alkalosis. Conversely, hyperkalaemia – a level above 5.5 mmol/L – can lead to serious heart problems, particularly in people suffering from kidney failure or taking certain cardiovascular treatments (EFSA, 2006).