The sodium content of 13 liquid antacids was determined using two independent analytical methods (flame photometry). With a neutralisation buffering capacity of 564 mmol/d (pH 3.5) the possible body sodium load was calculated by evaluating the sodium content in the supernatant of the antacid suspensions, ranging from 0.56 to 568 mmol/d (method A) and from 0.42 to 468 mmol/d (method B). Therefore, in patients who are on a sodium restriction of 50 mmol/d this critical intake may be easily exceeded by the intake of certain antacids.