title: Vitamin D deficiency in elderly women in nursing homes: investigation with consideration of decreased activation function from the kidneys.
abstract: OBJECTIVE
  To determine the approximate percentage of women in nursing homes who have vitamin D deficiency and to investigate whether, in assessing vitamin D status in elderly women, there are problems with measuring only 25 hydroxy-vitamin D(3)  (25(OH)D(3) ) and whether decreased vitamin D activation as a result of poor renal function needs to be considered.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Forty-eight nursing homes in Japan.
  
  
  METHODS
  Four hundred three women with a mean age of 86.5 living in nursing homes who had participated in a clinical trial for hip protectors and were not bedridden.
  
  
  METHODS
  At the start of the trial, in addition to general biochemical data, 25(OH)D(3) , 1,25-dihydroxy-vitamin D(3)  (1,25(OH)(2) D(3) ), intact parathyroid hormone (intact PTH), calcium (Ca), phosphorus (P), bone alkaline phosphate (BAP), cross-linked N-telopeptide of type I collagen (NTx), and osteocalcin were measured in participants' blood, and statistical analysis was performed.
  
  
  RESULTS
  25(OH)D(3) , which is thought to reflect vitamin D status in the body, was surveyed and found to have a mean value of 16.7 ng/mL. 25(OH)D(3)  was less than 16 ng/mL in 49.1% of all participants. Creatinine clearance (CCr) was less than 30 mL/min in 20.1% of participants. Participants with serum 25(OH)D(3)  less than 16 ng/mL and CCr less than 30 mL/min had significantly higher levels of intact PTH and serum NTx. Participants with a CCr less than 30 mL/min had significantly lower levels of 1,25(OH)(2) D(3) .
  
  
  CONCLUSIONS
  Frail elderly adults living in nursing homes with poor renal function had lower 1,25(OH)(2) D(3)  and higher intact PTH levels and were thus thought to have poorer vitamin D activating capacity. Supplementation with cholecalciferol may be insufficient in people who have poor renal function.
authors.affiliation: Department of Orthopedic Surgery, National Center for Geriatrics and Gerontology, Obu City, Aichi, Japan. yst-trb@ncgg.go.jp
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Terabe
authors.forename: Atsushi
authors.initials: A
authors.lastname: Harada
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Tokuda
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Okuizumi
authors.forename: Masahiro
authors.initials: M
authors.lastname: Nagaya
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shimokata
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D006707:Homes for the Aged; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D009735:Nursing Homes; D014808:Vitamin D Deficiency / Q000453:epidemiology* / Q000209:etiology*