title: Unintentional doping through the use of contaminated nutritional supplements.
abstract: OBJECTIVE
  To determine whether the intake of contaminated nutritional supplements could cause an athlete to fail a dope test.
  
  
  METHODS
  A contaminated nutritional supplement was used, identified in an ongoing study screening over-the-counter nutritional supplements. One capsule of the supplement, containing small amounts of 19-nor-4-androstenedione and 4-androsten-3,17-dione, not listed on the label, was administered to 5 healthy male volunteers. Fractional urine collection was done at prescribed intervals. Outcome measures. The samples were analysed using gas chromatography/mass spectrometry (GC/MS). Samples containing 19-norandrosterone, the main metabolite of 19-nor-4-androstenedione, were quantified using GC/MS.
  
  
  RESULTS
  All the volunteers had urinary concentrations of 19-norandrosterone above the World Anti-Doping Agency threshold of 2 ng/ml from 2 hours post administration. In 2 volunteers 19-norandrosterone above the threshold value could still be detected beyond 36 hours post administration. The highest concentration of 19-norandrosterone found in a sample was 54.6 ng/ml at 8 hours post administration.
  
  
  CONCLUSIONS
  The results of this study showed that the intake of microgram amounts of a prohibited substance in a nutritional supplement could cause an athlete to fail a dope test.
authors.affiliation: South African Doping Control Laboratory, Department of Pharmacology, University of the Free State, Bloemfontein. gnfmpvdm.md@mail.uovs.ac.za
authors.forename: P J
authors.initials: PJ
authors.lastname: van der Merwe
authors.forename: E
authors.initials: E
authors.lastname: Grobbelaar
mesh_terms: D000328:Adult; D000734:Androstenediols; D000735:Androstenedione / Q000031:analogs & derivatives; D019587:Dietary Supplements; D004300:Doping in Sports; D004340:Drug Contamination; D004962:Estranes / Q000652:urine; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D000734:Androstenediols; D004962:Estranes; D000735:Androstenedione; C036015:19-norandrosterone; C002828:19-norandrostenedione