I have a hypokalemia, why does my doctor recomends potassium citrate?

To replace potassium: Oral supplements are commonly used to treat low potassium. In prescription form, Potassium Chloride is more commonly used. The bigger question is why do you have the low potassium in the first place? You're pretty young to be on a diuretic (water pill), the most common cause of low potassium.

To raise potassium.: Hypokalemia can be caused by certain renal conditions and drugs such as diuretics. The potassium is to keep your level in balance. Low potassium can cause cramps, raise blood pressure, and cause arrythmias!