Potassium - Information and Sources

Potassium is an electrolyte which assists in muscle contraction and in maintaining fluid and electrolyte balance in body cells. Potassium is also important in sending nerve impulses as well as releasing energy from protein, fat, and carbohydrates during metabolism.

Adults should aim to have at least 3,500mg of potassium per day, which with a balanced varied diet is quite easy. Deficiency of potassium causes muscle weakness, impaired heart function (in extreme cases will lead to death), mental depression and confusion.

Although abundant in the Western diet, potassium is a very labile micronutrient and is lost in cooking foods even under the best conditions. To retain as much potassium as possible cook foods in a minimal amount of water and for the shortest possible time with a cover or lid.

Potassium is generally plentiful in the diet, but good sources include:

  • Sweet potato, cooked, (150g) 450mg
  • Potato, baked (140g) – 882mg
  • Tomato puree (50g) – 575mg
  • Yogurt, plain, low-fat (150g) – 375mg
  • Prunes, in juice (150g) – 510mg
  • Avocado (130g) – 585mg
  • Apricots (110mg – 297mg
  • Bananas (135g) – 540mg
  • Raisins (35g) – 360mg
  • Mixed dried fruit (100g) – 880mg
  • Melon, cantaloupe (½ melon) – 755mg
  • Melon, galia (½ melon) – 540mg
  • Melon, honeydew (¼ melon) – 400mg
  • Watermelon (300g) – 300mg
  • Spinach, boiled (130g) – 650mg
  • Lentils, cooked (100g) – 310mg
  • Red kidney beans, cooked (100g) – 420mg
  • Soya beans, cooked (100g) – 510mg
  • Cod, baked (130g) – 455mg
  • Haddock, steamed (130g) – 420mg
  • Halibut, steamed (130mg) – 440mg
  • Plaice, steamed (130mg) – 364mg
  • Mackerel, smoked (130mg) – 400mg
  • Salmon, cooked (130g) – 430mg
  • Gammon (120g) – 300mg
  • Chicken (85g) – 245mg
  • Turkey (85g) – 264mg
  • Tomato juice (250ml) – 575mg
  • Orange juice (250ml) – 375mg
  • Milk, all types (250ml) – 375mg