- Personal history of kidney stones (by subjects' report); known allergy to any of the dietary supplements to be used in the study (by subjects' report); short bowel; active ulcerative colitis or irritable bowel disease; Crohns or Celiac disease; renal tubular acidosis; current use of topiramate or other carbonic anhydrase inhibitor, steroids, allopurinol, thiazide diuretics, or supplemental ascorbic acid >250 mg/day.