title: Elevated serum levels of Vitamin D in infants with urolithiasis.
abstract: BACKGROUND
  The pathophysiology of urolithiasis in infancy is not well known. The aim of this study was to investigate whether infants with urolithiasis have higher serum levels of vitamin D, as a possible risk factor for urolithiasis, compared to infants without urinary calculi.
  
  
  METHODS
  In this case-control study, 36 infants with urolithiasis (age range, 2.5 to 24 months) were enrolled as well as 36 age- and sex-matched infants without urolithiasis. Random urine samples were tested for calcium, phosphorous, oxalate, citrate, uric acid, sodium, potassium, magnesium, and creatinine levels, and also nitroprusside test was done on the samples. Serum levels of potassium, urea nitrogen, creatinine, 25-hydroxyvitamin D3, parathyroid hormone, calcium, phosphorous, and uric acid were measured in all of the infants with urolithiasis. Serum levels of 25-hydroxyvitamin D3 were also measured in the control group.
  
  
  RESULTS
  Serum levels of 25-hydroxyvitamin D3 were significantly higher in the infants with urolithiasis than in the controls (33.85 ± 14.78 ng/mL versus 18.26 ± 7.43 ng/mL, P < .001). Nine infants in the urolithiasis group (25%) were found to have hypercalcemia; 3 of these cases also had hypervitaminosis D. Hypercalciuria was detected in 10 infants with urolithiasis (27.8%), hypocitraturia in 6 (16.7%), hypomagnesiuria in 3 (8.3%), and hyperoxaluria in 1 (2.8%). Nineteen infants with urolithiasis had at least one metabolic disorder.
  
  
  CONCLUSIONS
  High serum levels of vitamin D may play an important role in the pathogenesis of urolithiasis in infants with hypercalcemia. We recommend evaluation of vitamin D levels in these infants.
authors.affiliation: Shiraz Nephro-Urology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Mohammad Hossein
authors.initials: MH
authors.lastname: Fallahzadeh
authors.forename: Javad
authors.initials: J
authors.lastname: Zare
authors.forename: Ghamar Hosseini
authors.initials: GH
authors.lastname: Al-Hashemi
authors.forename: Ali
authors.initials: A
authors.lastname: Derakhshan
authors.forename: Mitra
authors.initials: M
authors.lastname: Basiratnia
authors.forename: Mohammad Mehdi
authors.initials: MM
authors.lastname: Arasteh
authors.forename: Mohammad Amin
authors.initials: MA
authors.lastname: Fallahzadeh
authors.forename: Mohammad Kazem
authors.initials: MK
authors.lastname: Fallahzadeh
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D002112:Calcifediol / Q000378:metabolism*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007223:Infant; D007669:Kidney Calculi / Q000097:blood* / Q000209:etiology / Q000652:urine; D008297:Male; D012307:Risk Factors; D013472:Sunlight; D014807:Vitamin D / Q000008:administration & dosage; D014815:Vitamins / Q000008:administration & dosage
chemical_list: D015415:Biomarkers; D014815:Vitamins; D014807:Vitamin D; D002112:Calcifediol