title: Factors associated with vitamin D deficiency in a Norwegian population: the HUNT Study.
abstract: Vitamin D deficiency occurs worldwide. Winter season and high Body Mass Index (BMI) are associated with low levels of serum 25-hydroxyvitamin D (25(OH)D). We estimated the prevalence of vitamin D deficiency in a Norwegian adult population and examined factors associated with vitamin D deficiency. A cohort of 25, 616 adults (19-55 years) who participated in both the second and third Nord-Trøndelag Health Study (HUNT 2 (1995-1997) and HUNT 3 (2006-2008)) was established in a previous study. A 10% random sample of the cohort population was recruited for serum 25(OH)D measurements (n=2584), which was used for the current cross-sectional study. Vitamin D deficiency was defined as serum 25(OH)D level <50 nmol/L. The overall prevalence of vitamin D deficiency was 40%, but varied by season (winter: 64%; summer: 20%). Winter season (adjusted prevalence ratio (PR): 3.16, 95% CI 2.42 to 4.12) and obesity (BMI ≥30.0 kg/m2) (PR: 1.74, 95% CI 1.45 to 2.10) were strongly associated with prevalent vitamin D deficiency. Current smoking also demonstrated an increased PR (1.41, 95% CI 1.21 to 1.65). Daily intake of cod liver oil (PR: 0.60, 95% CI 0.41 to 0.77), increased physical activity (PR: 0.80, 95% CI 0.68 to 0.95) and more frequent alcohol consumption (PR: 0.76, 95% CI 0.60 to 0.95) were associated with a reduced PR. The prevalence of vitamin D deficiency was high in Norwegian adults. Winter season, high BMI and current smoking were positively associated, and intake of cod liver oil, increased physical activity and more frequent alcohol consumption were inversely associated with vitamin D deficiency.
authors.affiliation: Department of Public Health and General Practice, Faculty of Medicine, Norwegian University of Science and Technology, , Trondheim, Norway.
authors.forename: Tricia L
authors.initials: TL
authors.lastname: Larose
authors.forename: Yue
authors.initials: Y
authors.lastname: Chen
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Camargo
authors.forename: Arnulf
authors.initials: A
authors.lastname: Langhammer
authors.forename: Pål
authors.initials: P
authors.lastname: Romundstad
authors.forename: Xiao-Mei
authors.initials: XM
authors.lastname: Mai
mesh_terms: D000328:Adult; D000428:Alcohol Drinking / Q000453:epidemiology; D001800:Blood Specimen Collection; D015992:Body Mass Index; D003060:Cod Liver Oil / Q000008:administration & dosage; D015331:Cohort Studies; D015986:Confounding Factors, Epidemiologic; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology; D009664:Norway / Q000453:epidemiology; D009765:Obesity / Q000150:complications / Q000453:epidemiology; D011159:Population Surveillance; D015995:Prevalence; D012621:Seasons; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology*; D055815:Young Adult
chemical_list: D014807:Vitamin D; D003060:Cod Liver Oil; C104450:25-hydroxyvitamin D
keywords: Endocrinology; Epidemiology; Lifestyle