title: Associations of 25-hydroxyvitamin D2 and D3 with cardiovascular risk factors in childhood: cross-sectional findings from the Avon Longitudinal Study of Parents and Children.
abstract: BACKGROUND
  Studies in adults have reported associations of low circulating total 25-hydroxyvitamin D with increased cardiovascular disease and risk factors. Evidence of associations in children, however, is limited, and it is unknown whether associations with risk factors differ for each 25-hydroxyvitamin D analog [25-hydroxyvitamin D(2) (25[OH]D(2)) and 25-hydroxyvitamin D(2) (25[OH]D(3))].
  
  
  OBJECTIVE
  The objective of the study was to compare associations of 25(OH)D(2) and 25(OH)D(3) with cardiovascular risk factors in children.
  
  
  METHODS
  The design of the study was a cross-sectional study of 4274 children (mean age 9.9 yr) from the Avon Longitudinal Study of Parents and Children.
  
  
  RESULTS
  The main outcomes included blood pressure, lipids [triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol (HDL-C)], apolipoproteins (Apo-A1 and Apo-B), adiponectin, leptin, C-reactive protein, and IL-6.
  
  
  RESULTS
  In confounder-adjusted models, 25(OH)D(2) was inversely associated with Apo-A1 (change per doubling of exposure: -0.74 mg/dl; 95% confidence interval -0.14, -0.04) and triglycerides (relative percentage change per doubling of exposure: -1.64%; -3.27, 0.01) and positively associated with C-reactive protein (8.42%; 3.40, 13.58) and IL-6 (5.75%; 1.83, 9.25). 25(OH)D(3) was positively associated with HDL-C (0.04 mmol/liter; 0.02, 0.06), Apo-A1 (1.96 mg/dl; 0.65, 3.24), and adiponectin (0.47 μg/ml; 0.15, 0.79). There was statistical evidence that associations of 25(OH)D(2) and 25(OH)D(3) with HDL-C, Apo-A1, and IL-6 differed from each other (all P values for differences ≤0.02).
  
  
  CONCLUSIONS
  Higher circulating 25(OH)D(3) was associated with cardioprotective levels of HDL-C, Apo-A1, and adiponectin in children. Associations of 25(OH)D(2) with cardiovascular risk factors were in mixed directions. It is necessary to see whether these associations are replicated in large prospective studies.
authors.affiliation: Medical Research Council Centre for Causal Analyses in Translational Epidemiology, School of Social and Community Medicine, University of Bristol, Bristol BS8 2BN, United Kingdom. dylan.williams@bristol.ac.uk
authors.forename: Dylan M
authors.initials: DM
authors.lastname: Williams
authors.forename: Abigail
authors.initials: A
authors.lastname: Fraser
authors.forename: Adrian
authors.initials: A
authors.lastname: Sayers
authors.forename: William D
authors.initials: WD
authors.lastname: Fraser
authors.forename: Aroon
authors.initials: A
authors.lastname: Hingorani
authors.forename: John
authors.initials: J
authors.lastname: Deanfield
authors.forename: George
authors.initials: G
authors.lastname: Davey Smith
authors.forename: Naveed
authors.initials: N
authors.lastname: Sattar
authors.forename: Debbie A
authors.initials: DA
authors.lastname: Lawlor
mesh_terms: D015652:25-Hydroxyvitamin D 2 / Q000097:blood*; D052242:Adiponectin / Q000097:blood; D001053:Apolipoproteins / Q000097:blood; D001794:Blood Pressure / Q000502:physiology; D002097:C-Reactive Protein / Q000378:metabolism; D002112:Calcifediol / Q000097:blood*; D002318:Cardiovascular Diseases / Q000097:blood*; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood; D020738:Leptin / Q000097:blood; D008055:Lipids / Q000097:blood; D008297:Male; D012307:Risk Factors
chemical_list: D052242:Adiponectin; D001053:Apolipoproteins; D015850:Interleukin-6; D020738:Leptin; D008055:Lipids; D015652:25-Hydroxyvitamin D 2; D002097:C-Reactive Protein; D002112:Calcifediol