title: Profiles of vitamin D insufficiency and deficiency in Japanese men and women: association with biological, environmental, and nutritional factors and coexisting disorders: the ROAD study.
abstract: Assessments of serum 25-hydroxyvitamin D levels in 1,683 Japanese from a population-based cohort revealed prevalences of vitamin D insufficiency and deficiency were 81.3 and 1.2%, respectively. Vitamin D deficiency was significantly associated with female sex, examined month, current smoking, lack of regular walking, higher intact parathyroid hormone (iPTH), and poor daily vitamin D intake.
  
  
  BACKGROUND
  To clarify the characteristics of subjects with vitamin D insufficiency and deficiency among men and women in the general Japanese population.
  
  
  METHODS
  We initiated research on osteoarthritis/osteoporosis against disability (ROAD), a large-scale population-based cohort study, in 2005-2007. Blood examination was performed to measure serum 25-hydroxyvitamin D (25D) and iPTH levels and biochemical markers of bone turnover in 1,683 participants (595 men, 1,088 women). Participants completed an interviewer-administered questionnaire, measurements of bone mineral density, and x-ray examination. Vitamin D deficiency and insufficiency were defined by serum 25D levels <10 and ≥10 but <30 ng/mL, respectively.
  
  
  RESULTS
  The prevalence of vitamin D insufficiency and deficiency was 81.3 and 1.2%, respectively. Multinominal logistic regression analyses using potentially confounding variables revealed vitamin D insufficiency was significantly associated with age (+1 year, relative risk ratio, 0.98; 95% confidence interval, 0.96-0.99), gender (women vs. men, 2.28; 1.59-3.30), residing areas (coastal area vs. mountainous area, 0.58; 0.41-0.81), examined month (October, November, December vs. January, 0.51; 0.34-0.76), and serum levels of iPTH (+1 pg/mL, 1.02; 1.01-1.03). Vitamin D deficiency was significantly characterised by female sex (20.5; 3.1-136.7), examined month (0.28; 0.09-0.95), current smoking habit (6.39; 1.78-23.0), lack of regular outside walking (3.96; 1.34-11.7), higher iPTH (1.02; 1.01-1.03) and poor daily vitamin D intake (+10 μg/day, 0.48; 0.24-0.93).
  
  
  CONCLUSIONS
  A high prevalence of vitamin D insufficiency and a low prevalence of vitamin D deficiency were found in Japanese men and women, and the characteristics of vitamin D status were clarified.
authors.affiliation: Department of Joint Disease Research, 22nd Century Medical and Research Center, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan, YOSHIMURAN-ORT@h.u-tokyo.ac.jp.
authors.forename: N
authors.initials: N
authors.lastname: Yoshimura
authors.forename: S
authors.initials: S
authors.lastname: Muraki
authors.forename: H
authors.initials: H
authors.lastname: Oka
authors.forename: M
authors.initials: M
authors.lastname: Morita
authors.forename: H
authors.initials: H
authors.lastname: Yamada
authors.forename: S
authors.initials: S
authors.lastname: Tanaka
authors.forename: H
authors.initials: H
authors.lastname: Kawaguchi
authors.forename: K
authors.initials: K
authors.lastname: Nakamura
authors.forename: T
authors.initials: T
authors.lastname: Akune
mesh_terms: D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000886:Anthropometry / Q000379:methods; D004777:Environment; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008019:Life Style; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D012621:Seasons; D017678:Sex Distribution; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology; D014807:Vitamin D / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology / Q000209:etiology*; D016138:Walking / Q000502:physiology
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D