Hi. Some bodybuilder said that 500mg per day are a maximum and should not be exceeded but he didn't give a reason. Does anyone know why this is the case and how much potassium someone should take per day? EDIT: Found sth. but I really don't get why 99mg are the upper limit. If I eat 5 medium sized potatoes I get 5g of potassium, which is 50 times the supplement concentration. http://lpi.oregonstate.edu/infocenter/minerals/potassium/ Supplements Multivitamin-mineral supplements in the U.S. do not contain more than 99 mg of potassium per serving. Higher doses of supplemental potassium are generally prescribed to prevent and treat potassium depletion and hypokalemia. The use of more potent potassium supplements in potassium deficiency requires close monitoring of serum potassium concentrations. Potassium supplements are available as a number of different salts, including potassium chloride, citrate, gluconate, bicarbonate, aspartate and orotate (29). Because of the potential for serious side effects the decision to use a potent potassium supplement should be made in collaboration with one's health care provider (see Safety).