title: High prevalence of vitamin D deficiency, secondary hyperparathyroidism and generalized bone pain in Turkish immigrants in Germany: identification of risk factors.
abstract: BACKGROUND
  The aim of the study was to determine the prevalence of vitamin D deficiency, secondary hyperparathyroidism (sHPT), generalized bone pain and predictors of vitamin D deficiency in a cohort of 994 healthy adult urban residents (589 males, 405 females; age range: 16-69 years) consisting of 101 Germans, 327 Turkish residents of Turkey and 566 Turkish immigrants living in Germany.
  
  
  METHODS
  The mean (+/- standard deviation) for 25-hydroxyvitamin D [25(OH)D] and biointact parathyroid hormone (BioPTH) for the German men and women was 68.4 nmol/l and 26.7 pg/ml, respectively. Turkish residents of Turkey had a mean 25(OH)D and BioPTH of 40.6 nmol/l and 27.5 pg/ml, respectively, whereas Turkish residents of Germany had a 25(OH)D of 38.1 nmol/l and a BioPTH of 35.6 pg/ml.
  
  
  RESULTS
  Vitamin D insufficiency was common among Turkish nationals independent of whether they lived in Turkey or Germany; 75% had 25(OH)D levels of <50 nmol/l. Turkish females had a higher prevalence of 25(OH)D deficiency (<25 nmol/l) than Turkish males: 30 and 19% of Turkish females living in Germany and Turkey were severely vitamin D deficient compared to 8% and 6% of Turkish males living in Germany and Turkey, respectively. With respect to BioPTH levels, 31% of Turkish females and 21% of Turkish males had elevated BioPTH levels in contrast to only 15% of females and 4% of males living in Turkey. Unconditional logistic regression analysis identified the most important predictors for low 25(OH)D levels as sex, body mass index, lack of sun exposure and living at a higher latitude. Additionally, wearing a scarf and number of children were found to be an independent risk factor for vitamin D deficiency in Turkish women living in Turkey and Germany. A strong correlation between low 25(OH)D levels and higher rates and longer duration of generalized bone and/or muscle aches and pains (often diagnosed as fibromyalgia) was observed.
  
  
  CONCLUSIONS
  Secondary hyperparathyroidism and vitamin D deficiency was found to be common among Turkish immigrants living in Germany, especially in veiled women. Therefore, the monitoring of vitamin D status--i.e. 25(OH)D and PTH--in Turkish immigrants is warranted and once a deficiency is identified, it should be appropriately treated.
authors.affiliation: Third Medical Department and Policlinic, University of Giessen Medical Centre, Giessen, Germany.
authors.forename: M Z
authors.initials: MZ
authors.lastname: Erkal
authors.forename: J
authors.initials: J
authors.lastname: Wilde
authors.forename: Y
authors.initials: Y
authors.lastname: Bilgin
authors.forename: A
authors.initials: A
authors.lastname: Akinci
authors.forename: E
authors.initials: E
authors.lastname: Demir
authors.forename: R H
authors.initials: RH
authors.lastname: Bödeker
authors.forename: M
authors.initials: M
authors.lastname: Mann
authors.forename: R G
authors.initials: RG
authors.lastname: Bretzel
authors.forename: H
authors.initials: H
authors.lastname: Stracke
authors.forename: M F
authors.initials: MF
authors.lastname: Holick
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002118:Calcium / Q000097:blood; D003430:Cross-Sectional Studies; D004641:Emigration and Immigration; D005260:Female; D005356:Fibromyalgia / Q000453:epidemiology*; D005858:Germany / Q000453:epidemiology; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D010018:Osteomalacia / Q000453:epidemiology*; D010281:Parathyroid Hormone / Q000097:blood; D015995:Prevalence; D012307:Risk Factors; D014421:Turkey; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000453:epidemiology*
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D002118:Calcium