Minerals and why we need them
Potassium RDA 2000mg.
A correct balance of extracellular and intracellular potassium is necessary to maintain nerve cell resting membrane potential.
Potassium is an essential dietary mineral that is also known as an electrolyte. The term electrolyte refers to a substance that dissociates into ions (charged particles) in solution making it capable of conducting electricity. The normal functioning of our bodies depends on the tight regulation of potassium concentrations both inside and outside of cells.
Think of a battery. A battery has electrolytes, and when these electrolytes decline and go off balance the battery loses energy and becomes weak. This also happens within the body when its electrolytes decline or go off balance. It is recognised that as we age the levels of ions in the interstitial fluids decline.
Potassium is the principal, positively charged ion (cation) in the fluid inside the cells, while sodium is the principal cation in the fluid outside the cells. Potassium concentrations are about 30 times higher inside than outside the cells, while sodium concentrations are more than 10 times lower inside than outside the cells. The concentration differences between potassium and sodium across cell membranes creates an electrochemical gradient known as the membrane potential.
A cell's membrane potential is maintained by ion pumps in the cell membrane, especially the sodium, potassium-ATPase pumps. These pumps use ATP (energy) to pump sodium out of the cell in exchange for potassium. Their activity has been estimated to account for 20%-40% of the resting energy expenditure in a typical adult. The large proportion of energy dedicated to maintaining sodium/potassium concentration gradients emphasises the importance of this function. Tight control of cell membrane potential is critical for nerve impulse transmission, muscle contraction, and heart function.
Too many acidic foods in the diet causes the body to use up potassium reserves to buffer the body's acidity.Potassium's role within the nervous system
The nervous system, along with all other functions within the body, is highly dependent on the sodium potassium pump (ion pump) working correctly, so it is vital that a balanced level of these two minerals is present at all times to maintain good health.Problems associated with altered potassium levels
Imbalances of potassium can be responsible for lethargy, lassitude, learning difficulties and depression. A fall in intracellular levels can result in irritability, insomnia, over-sensitivity and hyperactivity. A fall in extracellular levels can cause depression of nervous function, lack of reaction to stimuli and poor concentration.
Temporary loss of potassium can result from profuse sweating (heavy exercise, viral infections), or diarrhoea and vomiting, which can also be a concern in infants. Severe potassium loss can cause death.Symptoms associated with potassium deficiency
Anxiety - nervousness - fatigue - diabetes - hypoglycaemia - heart strain - high blood pressure - liver problems - lower back pain - muscle weakness - multiple sclerosis - overweight - stroke - high blood pressure - congestive heart failure - cardiac arrhythmias - palpitations - muscle weakness - hyperthyroid - blood sugar disorders - mental apathy - depression - erectile dysfunction (impotence) - fatigue and general weakness.Best food sources
Fruits, especially bananas and dried fruits - potatoes - tomatoes - molasses - soya flour.