Potassium

Potassium is an essential mineral and electrolyte that plays a vital role in maintaining fluid balance, nerve signalling, and muscle function, including heart rhythm regulation. It supports bone health by reducing calcium loss and helps counteract sodium’s effects on blood pressure, lowering cardiovascular risks. Research highlights its efficacy in managing hypertension, with studies showing modest but significant reductions in systolic and diastolic blood pressure from supplementation. A diet rich in potassium is linked to reduced stroke risk and improved kidney function.

Key Facts

  • Adults require 3,400 mg (men) or 2,600 mg (women) of potassium daily, though higher intakes (3,500–5,000 mg) may benefit blood pressure.
  • Top dietary sources include bananas, potatoes, spinach, beans, dried apricots, and fish like salmon.
  • Potassium deficiency (hypokalaemia) can cause muscle weakness, fatigue, and irregular heart rhythms.
  • Excessive potassium intake via supplements may harm those with kidney disease or certain medications.
  • The mineral helps offset sodium’s blood pressure effects, easing blood vessel tension.
  • Whole foods are preferred over supplements due to better nutrient balance and lower risks.

What does the research say about potassium and its function in the body?

Potassium regulates fluid balance, nerve impulses, and muscle contractions, including heartbeats. Studies show it lowers blood pressure by countering sodium and relaxing blood vessels, reducing stroke and heart disease risks. It also supports bone density by minimising calcium loss in urine.

What are the primary food sources of potassium?

Rich sources include baked potatoes (with skin), dried apricots, spinach, lentils, bananas, and dairy products like yoghurt. Fish such as salmon and tuna also provide potassium, alongside tomato-based products and squash.

How can I supplement potassium?

Supplements (e.g., potassium chloride) should only be used under medical supervision, particularly for those with deficiencies or hypertension. Most people can meet their needs through diet alone, as over-the-counter supplements risk excessive intake.

What are the main symptoms of potassium deficiency?

Early signs include fatigue, muscle cramps, and constipation. Severe deficiency may cause palpitations, tingling, or paralysis. Chronic low levels increase kidney stone and arrhythmia risks.

Are there any known side effects of supplementing potassium?

Over-supplementation can cause hyperkalaemia (high potassium), leading to nausea, irregular heartbeat, or cardiac arrest, especially in those with kidney issues. Always consult a doctor before taking supplements.

How long does it take to see the benefits of potassium supplementation?

Blood pressure improvements may appear within weeks while correcting a deficiency can yield energy and muscle benefits within days. Long-term benefits, like reduced stroke risk, require consistent dietary intake.

What should consumers look for on the supplement label when supplementing potassium?

Opt for USP-verified products with clear "elemental potassium" amounts. Avoid salt substitutes (often potassium-based) unless advised, and check for interactions with medications like ACE inhibitors.

Does potassium interact with medications?

Yes, potassium can interact with diuretics, blood pressure drugs, and NSAIDs. Those on ACE inhibitors or potassium-sparing diuretics should monitor intake closely to avoid hyperkalaemia.

Can too much potassium be harmful?

Excess potassium (hyperkalaemia) is dangerous, causing symptoms like vomiting, arrhythmias, or heart failure. Those with kidney disease or on certain medications are most at risk.

How does potassium affect exercise performance?

Adequate potassium prevents muscle cramps and supports endurance by maintaining electrolyte balance. Deficiencies may impair muscle recovery and energy levels during physical activity.

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