Potassium
A key factor in maintaining health

Functions of Potassium in the body

• Regulates heart function
• Reduces blood pressure
• Essential for protein and nucleid acid synthesis
• Required for normal fluid balance
• Fundamental for normal nerve and muscle function
• Converts glucose into glycogen (muscle fuel)
• Important role in kidney function
• Helps lungs eliminate carbon dioxide
• Needed to maintain acid/alkali balance

Potassium is an essentially "intracellular", positively charged ion, which is actively "pumped" in to the cell from surrounding extracellular fluid, whilst its opponent, sodium, is pumped out. This is not only necessary for proper fluid balance, and creates an electrical charge across the cell membrane. This is also the fundamental principle which allows nerves to conduct "electrical" impulses and so communicate between cells and muscles to contract.

As the heart is a large muscle that is continually, rhythmically contracting, potassium is extremely important to proper heart function. Since it also controls the creation of glycogen (used by muscles for fuel) from glucose (blood sugar), it also controls the muscular fuel supply.

Potassium deficiency

The first signs of potassium deficiency are tiredness and muscle weakness. Whilst these are relatively unthreateneing consequences, things can quickly get a lot worse. Severe potassium deficiency quickly leads to electrolyte imbalance which affects all muscles, nerves and numerous key body functions.

Symptoms of Potassium deficiency

Nerve and muscle dysfunction
Water retention
Heart arrythmias (rhythm disturbances, palpitations)
Muscle weakness
Confusion
Poor kidney function
Continual thirst
Low blood pressure
Vomiting (also increases rate of potassium loss)

Association with other minerals and vitamins

Intimately involved with sodium to control electrolyte balance. These two positive ions are balanced by the negative chloride ion.

Factors which increase Potassium excretion

Sweating (can account for loss of 3000mg per day
Vomiting
Diarrhoea
Excessive tea / coffee / caffeinated drinks
Diuretic medication
Some antibiotics

Potassium excretion is mainly by the kidneys. Individualy with kidney disease may therefore have reduced potassium ecretion and show signs of potassium toxicity.

Normal amounts of Potassium in the diet

Sources of dietary Potassium

Because of its direct opposition to sodium, dietary sources of potassium should always consider the balance between the two when the intention is to increase potassium levels

Medicine has long maintained that the excess of sodium in the Western diet is implicated in the levels of heart disease, stroke and cancer. Whilst is is clear that sodium can cause problems in excessive amounts, such research usually ignores fundamental aspects such as the role of trans-fatty acids (ignored by medicine until very recently), antioxidants, overall nutrition and even the importance of water intake.

Potassium supplements

Levels of potassium in food must be balanced against levels of sodium, as in the table above. In many cases, the imbalance is due to excessive sodium intake rather than insufficient potassium.

Whilst it is normal for some potassium to be included in a multimeral formula, it is not normally recommended to take potassium supplements singly. Common sources of sodium, such as salt now have alternatives that use potassium instead of sodium, helping both sides of the equation.

In the few cases where potassium supplementation is required, it should be taken under clinical direction, and should be taken along with zinc and magnesium.

People taking medication for heart diease, hypertension (high blood pressure) and those with kidney disease should take potassium supplements only under the direction of a medical practitioner.

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