title: [Low vitamin D levels among patients at Semmelweis University: retrospective analysis during a one-year period].
abstract: Even in developed countries the prevalence of subjects with suboptimal vitamin D levels is high. The aim of this retrospective data analysis was to evaluate the prevalence of severe and moderate vitamin D deficiencies (defined as vitamin D levels<15 ng/ml and 15-30 ng/ml, respectively) among patients evaluated at Semmelweis University during a period between April, 2009 and March, 2010.
  
  
  RESULTS
  The average vitamin D level of 5808 subjects (3936 women and 1872 men) was 25.5 ± 10.9 ng/ml. The prevalence of moderate and severe vitamin D deficiency in whole population was 72% and 12%, respectively. Higher than normal vitamin D levels were measured in 0.8% of subjects. Female gender, older age and winter season were independent risk factors for vitamin D deficiency. Vitamin D levels were measured repeatedly in 1307 subjects. Interestingly, vitamin D levels measured later were lower compared to those measured at the first time (27.07±13.2 vs. 25.9±9.11 ng/ml, p<0.001). The prevalence of severe and moderate vitamin D deficiency was 8.1 and 71.5 per cent when vitamin D levels were measured at the second time. Of the 110 patients with severe vitamin D deficiency measured repeatedly only 11 patients (10%) presented with normal vitamin D levels at the second time.
  
  
  CONCLUSIONS
  These data indicate that severe and moderate vitamin D deficiencies are common in patients evaluated at Semmelweis University. Repeated measurements of vitamin D levels raise the notion that the efficacy of supplementation used for correction of vitamin D levels is not optimal.
authors.affiliation: Semmelweis Egyetem, Általános Orvostudományi Kar Laboratóriumi Medicina Intézet, Budapest, Bókay J. u. 54. 1085. vasbar@gyer1.sote.hu
authors.forename: Barna
authors.initials: B
authors.lastname: Vásárhelyi
authors.forename: Anna
authors.initials: A
authors.lastname: Sátori
authors.forename: Ferenc
authors.initials: F
authors.lastname: Olajos
authors.forename: András
authors.initials: A
authors.lastname: Szabó
authors.forename: Gabriella
authors.initials: G
authors.lastname: Beko
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D050071:Bone Density Conservation Agents / Q000008:administration & dosage; D002648:Child; D002675:Child, Preschool; D004872:Ergocalciferols / Q000008:administration & dosage; D005260:Female; D006785:Hospitals, University / Q000706:statistics & numerical data; D006801:Humans; D006814:Hungary / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D012621:Seasons; D017678:Sex Distribution; D014481:United States / Q000453:epidemiology; D014807:Vitamin D / Q000008:administration & dosage* / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology*
chemical_list: D050071:Bone Density Conservation Agents; D004872:Ergocalciferols; D014807:Vitamin D