Minerals - Potassium (K)

Question 1

Potassium (K)

Answer 1

• Potassium (K) Is the principal cation inside body cells and along with sodium chloride, it is a key electrolyte in the body

Question 2

Food sources

Answer 2

Widely distributed but highest in plant sources

Key food sources / Per 100g:
Vegetables: Raw spinach, baked potato with skin / 558 mg
Fruit: Avocado, banana, kiwi, melon, papaya / 396 mg
Grains: Quinoa, rye flour, buckwheat, oats / 740 mg
Nuts/seeds: Pistachio, sunflower, pumpkin / 1042 mg
Seafood: Clam, Crab, red snapper, Salmon / 628 mg
Meat/dairy: Calf’s liver, pork, cheddar (98 mg) / 364 mg

Question 3

Functions:
Osmotic pressure and electrolyte balance

Enzyme co-factor

Answer 3

Functions: Osmotic pressure and electrolyte balance
* The concentration difference of potassium and sodium across cell membranes is critical for:
o Nerve transmission (action potentials)
o Muscle function
Functions: Enzyme co-factor
* Potassium as co-factor for enzymes involved in energy metabolism, glycogenesis, cellular growth and division
Therapeutic uses:
* Rarely used therapeutically – except in hypertension
* Electrolyte loss e.g. post-diarrhoea, and following prolonged exercise– consider using coconut water (1 cup (250 ml) coconut water = 600 mg potassium)

Question 4

Deficiency:

Answer 4

• Potassium levels are very tightly regulated by homoeostatic mechanisms in the kidneys
• Deficiency (Hypokalaemia) usually results from excessive losses
  Causes of deficiency:
• Diuretics that enhance K loss
• Diarrhoea
• Vomiting
• Laxative abuse
• Chronic renal disease
  Hypokalaemia = low blood potassium

Question 5

Signs and symptoms of deficiency

Answer 5

• Muscle cramps/ fatigue/ weakness
• High blood pressure/ irregular beat
• Mental confusion/ fatigue/ irritability
• Insatiable thirst
• Insomnia

Question 6

Toxicity

Answer 6

• Potassium toxicity does not occur from over-eating K-rich foods
• However, it can result from excessive potassium salts, supplements or certain diseases (e.g. kidney failure). Due to the risk with supplements, always try to increase K using foods
• Acute potassium toxicity from supplements can lead to cardiac arrest
• Chronic potassium toxicity can lead to cardiac regularities, paralysis of extremities, mental confusion, tingling, weakness, kidney failure and adrenal insufficiency