title: Serum 25-hydroxyvitamin D concentrations and related dietary factors in peri- and postmenopausal Japanese women.
abstract: BACKGROUND
  Few studies of vitamin D nutrition in Asian populations have been conducted.
  
  
  OBJECTIVE
  The objective was to assess 25-hydroxyvitamin D [25(OH)D] concentrations in healthy elderly Japanese women during the winter and to determine whether 25(OH)D concentrations are associated with lifestyle.
  
  
  METHODS
  We investigated 151 women aged 66.5 +/- 6.7 y (f1.gif" BORDER="0"> +/- SD) living in a rural community in February 1999. Serum 25(OH)D and intact parathyroid hormone were measured by using HPLC and an immunoradiometric assay, respectively. Information on lifestyle factors, including sunshine exposure and the consumption of vitamin D-rich foods, was also obtained through an interview.
  
  
  RESULTS
  The mean (+/-SD) 25(OH)D concentration was 59.9 +/- 17.0 nmol/L. Vitamin D insufficiencies (<30 nmol/L) were found in 4.6% of the women, a value lower than that found in white populations. No correlation was found between age and 25(OH)D concentrations (r = 0.004, P = 0.957). The 25(OH)D concentration of subjects who consumed fish frequently (>/=4 times/wk) was 10.1 nmol/L higher (P < 0.001) than that of subjects with a moderate consumption of fish (1-3 times/wk). Additionally, those who did not consume eggs had significantly lower 25(OH)D concentrations than did those who consumed eggs >/=1 time/wk (P < 0.05).
  
  
  CONCLUSIONS
  : The nutritional status of vitamin D in Japanese populations seems to be better than that in most Western populations. Frequent fish consumption is believed to help maintain adequate concentrations of serum 25(OH)D in elderly Japanese women during the winter.
authors.affiliation: Department of Hygiene and Preventive Medicine, Niigata University School of Medicine, Niigata, Japan. kazun@med.niigata-u.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Nakamura
authors.forename: M
authors.initials: M
authors.lastname: Nashimoto
authors.forename: Y
authors.initials: Y
authors.lastname: Hori
authors.forename: M
authors.initials: M
authors.lastname: Yamamoto
mesh_terms: D015652:25-Hydroxyvitamin D 2 / Q000097:blood*; D000363:Agaricales; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D002112:Calcifediol / Q000097:blood*; D002851:Chromatography, High Pressure Liquid; D004531:Eggs; D005260:Female; D005399:Fishes; D006801:Humans; D007564:Japan; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000209:etiology*; D010281:Parathyroid Hormone / Q000097:blood; D017698:Postmenopause; D017697:Premenopause; D011863:Radioimmunoassay; D012424:Rural Population; D018709:Statistics, Nonparametric; D013472:Sunlight; D014808:Vitamin D Deficiency / Q000097:blood / Q000209:etiology*
chemical_list: D010281:Parathyroid Hormone; D015652:25-Hydroxyvitamin D 2; D002112:Calcifediol