title: Effect of L-arginine dietary supplementation on salivary urea concentration and pH in physically active individuals.
abstract: BACKGROUND
  The aim of this study was to assess if the consumption of 3 g of a commercially available L-arginine dietary supplement causes a postabsorptive rise in urea concentration or pH of unstimulated saliva in a group of physically active individuals.
  
  
  METHODS
  Salivary urea and pH were determined for 117 participants in a randomized double-blinded placebo-controlled study. Samples were collected by 'spitting' method in fasting conditions. One hour prior to their second visit, participants consumed three tablets of L-arginine or placebo.
  
  
  RESULTS
  Urea concentration was significantly lower at second measurement for both the study and control group. The magnitude of the change was not significant between the groups. pH was higher for both groups at second measurement, but only significant for the study group. The magnitude of the change was significant between the groups. Participants who intermittently ingested protein dietary supplements and those with a Body Mass Index (BMI) higher than 25 had significantly higher basal urea concentration.
  
  
  CONCLUSIONS
  The results of this study did not confirm the hypothesis. Further studies are needed to determine the effects of different doses of L-arginine supplements on the biochemical composition of saliva and the influence of their long-term consumption on the risk of developing dental diseases.
authors: Department of Physiology, School of Dental Medicine, University of Zagreb, Zagreb, Croatia.
authors: L
authors: L
authors: Vuletic
authors: S
authors: S
authors: Spalj
authors: D
authors: D
authors: Rogic
authors: L
authors: L
authors: Ruzic
authors: I
authors: I
authors: Alajbeg
mesh_terms: D001120:Arginine / Q000008:administration & dosage* / Q000378:metabolism; D003731:Dental Caries / Q000517:prevention & control; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D012463:Saliva / Q000737:chemistry* / Q000378:metabolism; D012737:Sex Factors; D014508:Urea / Q000032:analysis* / Q000378:metabolism; D055815:Young Adult
chemical_list: D014508:Urea; D001120:Arginine
keywords: L-arginine; oral health promotion; salivary pH; salivary urea; unstimulated saliva