title: Fish oil supplementation and urinary oxalate excretion in normal subjects on a low-oxalate diet.
abstract: OBJECTIVE
  To determine if fish oil supplementation reduces endogenous oxalate synthesis in healthy subjects.
  
  
  METHODS
  Fifteen healthy non-stone-forming adults participated in this study. Subjects first abstained from using vitamins, medications, or foods enriched in omega-3 fatty acids for 30 days. Next, they collected two 24-hour urine specimens while consuming a self-selected diet. Subjects consumed an extremely low-oxalate and normal-calcium diet for 5 days and collected 24-hour urine specimens on the last 3 days of this diet. Next, the subjects took 2 fish oil capsules containing 650-mg eicosapentaenoic acid and 450-mg docosahexaenoic acid twice daily for 30 days. They consumed a self-selected diet on days 1-25 and the controlled diet on days 26-30. Twenty-four-hour urine samples were collected on days 28-30. Excretion levels of urinary analytes including oxalate and glycolate were analyzed.
  
  
  RESULTS
  Although there was a significant reduction in urinary oxalate, magnesium, and potassium excretions and an increase in uric acid excretion during the controlled dietary phases compared with the self-selected diet, there were no significant differences in their excretion during controlled diet phases with and without fish oil supplementation.
  
  
  CONCLUSIONS
  These results suggest that fish oil supplementation does not reduce endogenous oxalate synthesis or urinary oxalate excretion in normal adults during periods of extremely low oxalate intake. However, these results do not challenge the previously described reduction in urinary oxalate excretion demonstrated in normal subjects consuming a moderate amount of oxalate in conjunction with fish oil.
authors.affiliation: Department of Urology, Wake Forest Baptist Health, Winston-Salem, NC. Electronic address: jelange@wakehealth.edu.
authors.forename: Jessica N
authors.initials: JN
authors.lastname: Lange
authors.affiliation: Department of Urology, George Washington University Medical Center, Washington, DC.
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Mufarrij
authors.affiliation: Department of Urology, Wake Forest Baptist Health, Winston-Salem, NC.
authors.forename: Linda
authors.initials: L
authors.lastname: Easter
authors.affiliation: Department of Urology, University of Alabama-Birmingham Medical Center, Birmingham, AL.
authors.forename: John
authors.initials: J
authors.lastname: Knight
authors.affiliation: Department of Urology, University of Alabama-Birmingham Medical Center, Birmingham, AL.
authors.forename: Ross P
authors.initials: RP
authors.lastname: Holmes
authors.affiliation: Department of Urology, University of Alabama-Birmingham Medical Center, Birmingham, AL.
authors.forename: Dean G
authors.initials: DG
authors.lastname: Assimos
mesh_terms: D000328:Adult; D004032:Diet; D019587:Dietary Supplements; D005260:Female; D005395:Fish Oils / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D010070:Oxalates / Q000008:administration & dosage / Q000652:urine*
chemical_list: D005395:Fish Oils; D010070:Oxalates
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