Oral supplementation of sodium, potassium and phosphate ions in extemporaneous preparation The article deals with the possibilities of oral supplementation of three selected ions - sodium, potassium and phosphate, by means of individually prepared medicines. It forms an overview of the most frequently used extemporaneous prescriptions in the University Hospital in Motol. It deals with the description of available raw materials and theoretical characteristics of ions. For selected formulations, the amount of ions is given in both mass and molar terms. The formulas reflect the need for ion supplementation in appropriate doses and appropriate dosage form according to the individual needs of patients.