title: Risk factors for vitamin D deficiency in patients with Crohn's disease.
abstract: BACKGROUND
  Although the pathogenesis of osteopenia in Crohn's disease is not established, vitamin D deficiency is thought to be an important risk factor. However, little is known about the prevalence of vitamin D deficiency in patients with Crohn's disease in Japan. This study aimed to clarify the prevalence of vitamin D deficiency in patients with Crohn's disease in Japan and to examine the possible causes of the deficiency.
  
  
  METHODS
  We investigated serum 25-hydroxyvitamin D (25-OHD) levels, various laboratory parameters, and patient histories in 33 outpatients (25 men, 8 women; median age, 37 years; range, 26-57 years) and 15 age- and sex-matched healthy controls (8 men, 7 women; median age, 37 years; range, 24-57 years) and assessed risk factors for vitamin D deficiency.
  
  
  RESULTS
  Although patients with Crohn's disease did not have significantly lower serum concentrations of 25-OHD than controls, 9 of 33 patients (27.3%) were considered vitamin D deficient (serum 25-OHD level </=10 ng/ml) compared with only 1 of 15 (6.7%) controls. Serum 25-OHD levels were significantly related to disease duration ( r = 0.46, P = 0.003), Crohn's Disease Activity Index (CDAI) score ( r = 0.44, P = 0.005), International Organization for the Study of Inflammatory Bowel Disease score ( r = 0.30, P < 0.05), and serum values of ferritin ( r = 0.34, P = 0.03), C-reactive protein ( r = 0.34, P = 0.03), total cholesterol ( r = 0.31, P = 0.04), and intact parathyroid hormone ( r = 0.23, P < 0.05). A logistic regression analysis was performed to investigate the ability of variables to predict low or normal 25-OHD values. Results showed that disease duration ( P = 0.03) and CDAI score ( P = 0.04) could predict the occurrence of vitamin D deficiency ( r(2) = 0.472, P = 0.0004).
  
  
  CONCLUSIONS
  Vitamin D deficiency exists in patients with Crohn's disease in Japan. 25-OHD levels should be assessed in patients who have had Crohn's disease for a long time (>15 years) and who have been in the active stage of the disease for long periods.
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, 464-8681, Nagoya, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Tajika
authors.forename: Akira
authors.initials: A
authors.lastname: Matsuura
authors.forename: Tsuneya
authors.initials: T
authors.lastname: Nakamura
authors.forename: Takashi
authors.initials: T
authors.lastname: Suzuki
authors.forename: Akira
authors.initials: A
authors.lastname: Sawaki
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Kato
authors.forename: Kazuo
authors.initials: K
authors.lastname: Hara
authors.forename: Kenji
authors.initials: K
authors.lastname: Ookubo
authors.forename: Kenji
authors.initials: K
authors.lastname: Yamao
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kato
authors.forename: Yasutoshi
authors.initials: Y
authors.lastname: Muto
mesh_terms: D000328:Adult; D003092:Colitis / Q000097:blood / Q000453:epidemiology; D015897:Comorbidity; D003424:Crohn Disease / Q000097:blood / Q000453:epidemiology*; D005260:Female; D005293:Ferritins / Q000097:blood; D006801:Humans; D007079:Ileitis / Q000097:blood / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000453:epidemiology*
chemical_list: D014807:Vitamin D; D005293:Ferritins; C104450:25-hydroxyvitamin D