An adult body contains about 250 g of potassium of which about 97% of the potassium in the body is in intracellular fluid intracellular fluid (intracellular fluid refer to fluid inside the cells) while the remainder being in the extracellular fluid compartments (extracellular fluid refers to fluid outside the cell).
1. Within the cell it maintains the osmotic pressure and fluid balance.
2. It is required for the synthesis of proteins.
3. It is required for enzymatic reactions taking place within the cell. Some Potassium is bound to phosphate and is required for the conversion of glucose to glycogen.
4. It is required for the transmission of nerve impulse and for contraction of muscle fibres.
It is widely distributed in foods. Meat, poultry and fish are good sources. Fruits, vegetables and whole grain cereals are especially high in potassium. Banana, potatoes, tomatoes, carrots, orange juice, grapefruit juice are rich sources.
Primarily the deficiency of potassium is not seen. Impaired appetite, severe malnutrition, chronic alcoholism and burn injuries can disturb the acid base balance and lower osmotic pressure.