title: Vitamin D levels and cardiometabolic risk factors in Portuguese adolescents.
abstract: BACKGROUND
  Growing evidence suggests a possible association between low vitamin D levels and increased cardiovascular risk. However, research regarding the period of adolescence is scarce. We aimed to evaluate the association of vitamin D, intake and serum 25(OH)D levels, with cardiometabolic risk factors in 13-year-old adolescents.
  
  
  METHODS
  We conducted a cross-sectional analysis of 1033 adolescents evaluated at 13years old as part of the population-based cohort EPITeen. Vitamin D intake was assessed by a food frequency questionnaire. Serum 25(OH)D levels were assessed for a subsample of 514 participants. Metabolic syndrome (MetS) features were defined according to the National Cholesterol Education Program Adult Treatment Panel III definition modified for age. Logistic regression was fitted to estimate the association between vitamin D status and cardiometabolic risk factors, adjusting for sex, parental education, BMI, physical activity and season.
  
  
  RESULTS
  Mean (SD) vitamin D levels, 4.61 (2.50)μg for intake and 16.52 (5.72)ng/mL for serum, were below the recommendations. The prevalence of MetS was 13.2%. Total cholesterol and LDL levels significantly decreased with 25(OH)D serum increase. After adjustment, no association was found between vitamin D levels and MetS. Regarding MetS features, an increased odds of high BMI was observed for those with a lower intake (OR 1.87 95% CI 1.04-3.35).
  
  
  CONCLUSIONS
  Although a significant increase in total and LDL cholesterol was observed for lower 25(OH)D levels, and an increased odds of high BMI was observed for those with a lower vitamin D intake, no significant association was observed between vitamin D levels and metabolic syndrome.
authors.affiliation: ISPUP-EPI Unit, Universidade do Porto, Rua das Taipas, nº 135, 4050-600 Porto, Portugal; Departamento de Epidemiologia Clínica, Medicina Preditiva e Saúde Pública, Faculdade de Medicina, Universidade do Porto, Al. Prof. Hernâni Monteiro, 4200 - 319 Porto, Portugal.
authors.forename: Maria
authors.initials: M
authors.lastname: Cabral
authors.affiliation: ISPUP-EPI Unit, Universidade do Porto, Rua das Taipas, nº 135, 4050-600 Porto, Portugal; Departamento de Epidemiologia Clínica, Medicina Preditiva e Saúde Pública, Faculdade de Medicina, Universidade do Porto, Al. Prof. Hernâni Monteiro, 4200 - 319 Porto, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Araújo
authors.affiliation: ISPUP-EPI Unit, Universidade do Porto, Rua das Taipas, nº 135, 4050-600 Porto, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Teixeira
authors.affiliation: ISPUP-EPI Unit, Universidade do Porto, Rua das Taipas, nº 135, 4050-600 Porto, Portugal; Departamento de Epidemiologia Clínica, Medicina Preditiva e Saúde Pública, Faculdade de Medicina, Universidade do Porto, Al. Prof. Hernâni Monteiro, 4200 - 319 Porto, Portugal.
authors.forename: Henrique
authors.initials: H
authors.lastname: Barros
authors.affiliation: ISPUP-EPI Unit, Universidade do Porto, Rua das Taipas, nº 135, 4050-600 Porto, Portugal; Department of Biochemistry, Faculty of Medicine, University of Porto, & Department of Clinical Pathology, São João Hospital Center, Porto, Portugal, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal.
authors.forename: Sandra
authors.initials: S
authors.lastname: Martins
authors.affiliation: ISPUP-EPI Unit, Universidade do Porto, Rua das Taipas, nº 135, 4050-600 Porto, Portugal; Department of Biochemistry, Faculty of Medicine, University of Porto, & Department of Clinical Pathology, São João Hospital Center, Porto, Portugal, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal.
authors.forename: João Tiago
authors.initials: JT
authors.lastname: Guimarães
authors.affiliation: ISPUP-EPI Unit, Universidade do Porto, Rua das Taipas, nº 135, 4050-600 Porto, Portugal; Departamento de Epidemiologia Clínica, Medicina Preditiva e Saúde Pública, Faculdade de Medicina, Universidade do Porto, Al. Prof. Hernâni Monteiro, 4200 - 319 Porto, Portugal.
authors.forename: Carla
authors.initials: C
authors.lastname: Lopes
authors.affiliation: ISPUP-EPI Unit, Universidade do Porto, Rua das Taipas, nº 135, 4050-600 Porto, Portugal; Departamento de Epidemiologia Clínica, Medicina Preditiva e Saúde Pública, Faculdade de Medicina, Universidade do Porto, Al. Prof. Hernâni Monteiro, 4200 - 319 Porto, Portugal. Electronic address: eliramos@med.up.pt.
authors.forename: Elisabete
authors.initials: E
authors.lastname: Ramos
mesh_terms: D000293:Adolescent; D001786:Blood Glucose / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000097:blood* / Q000453:epidemiology; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood* / Q000453:epidemiology; D011174:Portugal / Q000453:epidemiology; D012307:Risk Factors; D014807:Vitamin D / Q000008:administration & dosage / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood* / Q000453:epidemiology; D055105:Waist Circumference / Q000187:drug effects / Q000502:physiology
chemical_list: D001786:Blood Glucose; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D014807:Vitamin D
keywords: Adolescents; Metabolic syndrome; Vitamin D