title: Vitamin D levels and comorbidities in ambulatory and hospitalized patients in Austria.
abstract: Vitamin D in its hormonal active form, 1,25-dihydroxyvitamin D (calcitriol), has a major impact on bone turnover by regulating calcium and phosphate homoeostasis. By binding the active vitamin D hormone to the vitamin D receptor (VDR), it acts as a nuclear transcription factor (Bouillon et al., Endocr Rev 29(6):726-776, 2008). The discovery that almost all tissues and cells in the body express the VDR and that several tissues possess the enzymatic capability to convert 25-hydroxyvitamin D (25(OH)-D3; cholecalciferol) to the active form, suggests that vitamin D fulfills various extra-osseous functions (Bouillon et al., Endocr Rev 29(6):726-776, 2008; Holick, N Engl J Med 357(3):266-281, 2007). For example, VDR ensures adequate intestinal calcium absorption by regulating the synthesis of several calcium transport proteins in the duodenum (Bouillon et al., Endocr Rev 29(6):726-776, 2008). Additionally, vitamin D is important for proper muscle function, and some studies suggest it may contribute to prevent type 1 diabetes mellitus, certain autoimmune diseases, hypertension, and several types of cancer (Holick, N Engl J Med 357(3):266-281, 2007).
authors.affiliation: St. Vincent Hospital, Medical Department II, Academic Teaching Hospital of the Medical University of Vienna, Stumpergasse 13, 1060, Vienna, Austria. christian.muschitz@bhs.at.
authors.forename: Christian
authors.initials: C
authors.lastname: Muschitz
authors.affiliation: St. Vincent Hospital, Medical Department II, Academic Teaching Hospital of the Medical University of Vienna, Stumpergasse 13, 1060, Vienna, Austria.
authors.forename: Roland
authors.initials: R
authors.lastname: Kocijan
authors.affiliation: Department of Controlling and Medical Statistics, St. Vincent Hospital Vienna, Vienna, Austria.
authors.forename: Verena
authors.initials: V
authors.lastname: Stütz
authors.affiliation: Center for Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Vienna, Austria.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Kaider
authors.affiliation: Division of Plastic and Reconstructive Surgery, Department of Surgery, Medical University of Vienna, Vienna, Austria.
authors.forename: Gabriela Katharina
authors.initials: GK
authors.lastname: Muschitz
authors.affiliation: St. Vincent Hospital, Medical Department II, Academic Teaching Hospital of the Medical University of Vienna, Stumpergasse 13, 1060, Vienna, Austria.
authors.forename: Heinrich
authors.initials: H
authors.lastname: Resch
authors.affiliation: Labcon-Medical Laboratories Ltd., St. Vincent Group, Vienna, Austria.
authors.forename: Stylianos
authors.initials: S
authors.lastname: Kapiotis
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000553:Ambulatory Care; D001317:Austria / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D005260:Female; D006760:Hospitalization; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000097:blood* / Q000453:epidemiology*; D012307:Risk Factors; D017678:Sex Distribution; D014807:Vitamin D / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology*; D055815:Young Adult
chemical_list: D014807:Vitamin D
keywords: Age groups; Comorbidities; Cross-sectional study; Vitamin D deficiency