title: Noncitrus alkaline fruit: a dietary alternative for the treatment of hypocitraturic stone formers.
abstract: OBJECTIVE
  Fruits and vegetables are natural suppliers of potassium, bicarbonate, or bicarbonate precursors such as citrate, malate and others-hence, possessing potential effects on citraturia. We aimed to compare the acute effects of a noncitrus (melon) fruit vs citric ones (orange and lime) on citraturia and other lithogenic parameters.
  
  
  METHODS
  Two-hour urine samples were collected from 30 hypocitraturic stone-forming patients after an overnight fast and 2, 4, and 6 hours after the consumption of 385 mL (13 oz) of either freshly squeezed orange juice (n=10), freshly blended melon juice (n=10), or freshly squeezed lime juice (n=10). Urinary citrate, potassium, pH, and other lithogenic parameters were determined and net gastrointestinal alkali absorption (NGIA) was calculated. Potential renal acid load (PRAL) and pH from juices were determined.
  
  
  RESULTS
  Significant and comparable increases of mean urinary citrate were observed in all groups, whereas mean urinary potassium, pH, and NGIA were significantly increased only after consumption of melon and orange juices. The pH of melon juice was higher and the PRAL value was more negative compared with orange juice, indicating a higher alkalinity.
  
  
  CONCLUSIONS
  These findings suggested that melon, a noncitrus source of potassium, citrate, and malate, yielded an increase in urinary citrate excretion equivalent to that provided by orange, and hence represents another dietary alternative for the treatment of hypocitraturic stone-formers. Despite its low potassium content, lime also produced comparable increases in citraturia possibly because of its high citric acid content.
authors.affiliation: Nephrology Division, Universidade Federal de Sa˜o Paulo, Sa˜o Paulo, Brazil.
authors.forename: Leandro da Cunha
authors.initials: Lda C
authors.lastname: Baia
authors.forename: Alessandra Calábria
authors.initials: AC
authors.lastname: Baxmann
authors.forename: Silvia Regina
authors.initials: SR
authors.lastname: Moreira
authors.forename: Ross Philip
authors.initials: RP
authors.lastname: Holmes
authors.forename: Ita Pfeferman
authors.initials: IP
authors.lastname: Heilberg
mesh_terms: D000042:Absorption; D000328:Adult; D000468:Alkalies / Q000737:chemistry*; D019540:Area Under Curve; D001628:Beverages; D002951:Citrates / Q000652:urine; D019343:Citric Acid / Q000652:urine*; D032084:Citrus sinensis; D019662:Cucurbitaceae; D004032:Diet; D005260:Female; D005638:Fruit / Q000737:chemistry*; D006801:Humans; D007669:Kidney Calculi / Q000178:diet therapy* / Q000652:urine*; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000652:urine
chemical_list: D000468:Alkalies; D002951:Citrates; D019343:Citric Acid; D011188:Potassium