title: Calcium and vitamin D supplementation and risk of kidney stone formation in postmenopausal women.
abstract: BACKGROUND
  Calcium and vitamin D are essential structural components of the skeletal system, which prevent osteoporosis after menopause. However, there is a controversial debate on the association between the intake of calcium and vitamin D supplements and the increased risk of formation of kidney calculi in postmenopausal women. which yet have to be confirmed. This study aimed to compare the metabolic changes after supplementation of calcium and vitamin D and examine the risk of stone formation.
  
  
  METHODS
  Fifty-three postmenopausal women referred to rheumatology clinic who had no history of kidney calculi, bone diseases (apart from osteoporosis), metabolic, and rheumatic disorders and had not been receiving calcium, diuretics and calcitonin were investigated. Renal ultrasonography and blood tests were performed and the urine calcium levels were measured for a period of 24 hours for all patients. The examinations were repeated after a 1- year period of treatment with supplemental calcium (100 mg/d) and vitamin D (400 IU/d) and compared with the data before the treatment.
  
  
  RESULTS
  After 1 year, asymptomatic lithiasis was confirmed in 1 of 53 patients (1.9%) using ultrasonographic examination. No significant differences were found between the 24-hour urine and blood calcium levels before and after the treatment.
  
  
  CONCLUSIONS
  Our findings showed that oral intake of calcium and vitamin D after 1 year has no effect on the urinary calcium excretion rate and the formation of kidney calculi in postmenopausal women.
authors.affiliation: Division of Rheumatology, Tehran University of Medical Sciences, Tehran, Iran. a-haghighi@sina.tums.ac.ir
authors.forename: Anousheh
authors.initials: A
authors.lastname: Haghighi
authors.forename: Hamidreza
authors.initials: H
authors.lastname: Samimagham
authors.forename: Golnar
authors.initials: G
authors.lastname: Gohardehi
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood / Q000652:urine; D050071:Bone Density Conservation Agents / Q000008:administration & dosage / Q000009:adverse effects* / Q000652:urine; D002118:Calcium / Q000008:administration & dosage / Q000009:adverse effects* / Q000652:urine; D019587:Dietary Supplements / Q000009:adverse effects*; D004338:Drug Combinations; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000097:blood / Q000139:chemically induced* / Q000652:urine; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000517:prevention & control*; D017698:Postmenopause; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D014807:Vitamin D / Q000008:administration & dosage / Q000009:adverse effects*
chemical_list: D015415:Biomarkers; D050071:Bone Density Conservation Agents; D004338:Drug Combinations; D014807:Vitamin D; D002118:Calcium