title: Serum 25-hydroxyvitamin D concentrations and risk for hip fractures.
abstract: BACKGROUND
  The relationship between serum 25-hydroxyvitamin D [25(OH) vitamin D] concentration and hip fractures is unclear.
  
  
  OBJECTIVE
  To see whether low serum 25(OH) vitamin D concentrations are associated with hip fractures in community-dwelling women.
  
  
  METHODS
  Nested case-control study.
  
  
  METHODS
  40 clinical centers in the United States.
  
  
  METHODS
  400 case-patients with incident hip fracture and 400 control participants matched on the basis of age, race or ethnicity, and date of blood draw. Both groups were selected from 39 795 postmenopausal women who were not using estrogens or other bone-active therapies and who had not had a previous hip fracture.
  
  
  METHODS
  Serum 25(OH) vitamin D was measured and patients were followed for a median of 7.1 years (range, 0.7 to 9.3 years) to assess fractures.
  
  
  RESULTS
  Mean serum 25(OH) vitamin D concentrations were lower in case-patients than in control participants (55.95 nmol/L [SD, 20.28] vs. 59.60 nmol/L [SD, 18.05]; P = 0.007), and lower serum 25(OH) vitamin D concentrations increased hip fracture risk (adjusted odds ratio for each 25-nmol/L decrease, 1.33 [95% CI, 1.06 to 1.68]). Women with the lowest 25(OH) vitamin D concentrations (< or =47.5 nmol/L) had a higher fracture risk than did those with the highest concentrations (> or =70.7 nmol/L) (adjusted odds ratio, 1.71 [CI, 1.05 to 2.79]), and the risk increased statistically significantly across quartiles of serum 25(OH) vitamin D concentration (P for trend = 0.016). This association was independent of number of falls, physical function, frailty, renal function, and sex-steroid hormone levels and seemed to be partially mediated by bone resorption.
  
  
  CONCLUSIONS
  Few case-patients were nonwhite women. Bone mineral density and parathyroid hormone levels were not accounted for in the analysis.
  
  
  CONCLUSIONS
  Low serum 25(OH) vitamin D concentrations are associated with a higher risk for hip fracture.
authors: University of Pittsburgh, Department of Epidemiology, 130 DeSoto Street, Crabtree A524, Pittsburgh, PA 15261, USA. jcauley@edc.pitt.edu
authors: Jane A
authors: JA
authors: Cauley
authors: Andrea Z
authors: AZ
authors: Lacroix
authors: LieLing
authors: L
authors: Wu
authors: Mara
authors: M
authors: Horwitz
authors: Michelle E
authors: ME
authors: Danielson
authors: Doug C
authors: DC
authors: Bauer
authors: Jennifer S
authors: JS
authors: Lee
authors: Rebecca D
authors: RD
authors: Jackson
authors: John A
authors: JA
authors: Robbins
authors: Chunyuan
authors: C
authors: Wu
authors: Frank Z
authors: FZ
authors: Stanczyk
authors: Meryl S
authors: MS
authors: LeBoff
authors: Jean
authors: J
authors: Wactawski-Wende
authors: Gloria
authors: G
authors: Sarto
authors: Judith
authors: J
authors: Ockene
authors: Steven R
authors: SR
authors: Cummings
mesh_terms: D000058:Accidental Falls; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000368:Aged; D015992:Body Mass Index; D001862:Bone Resorption; D016022:Case-Control Studies; D005260:Female; D016330:Frail Elderly; D012739:Gonadal Steroid Hormones / Q000097:blood; D006304:Health Status; D006620:Hip Fractures / Q000097:blood* / Q000209:etiology*; D006801:Humans; D008875:Middle Aged; D016017:Odds Ratio; D010809:Physical Fitness; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D000305:Adrenal Cortex Hormones; D012739:Gonadal Steroid Hormones; D014807:Vitamin D; C104450:25-hydroxyvitamin D