title: Serum 25-hydroxyvitamin D and risk of venous thromboembolism: the Atherosclerosis Risk in Communities (ARIC) Study.
abstract: BACKGROUND
  Some evidence suggests that an inadequate vitamin D level may increase the risk for atherosclerotic cardiovascular disease. Whether a low vitamin D level plays a role in venous thromboembolism (VTE), that is, venous thrombosis and pulmonary embolism, is largely unexplored.
  
  
  OBJECTIVE
  We tested prospectively, in the Atherosclerosis Risk in Communities (ARIC) cohort, whether the serum level of 25-hydroxyvitamin D (25[OH]D) is inversely associated with VTE incidence, and whether it partly explains the African American excess of VTE in the ARIC Study.
  
  
  METHODS
  We measured 25(OH)D by using mass spectroscopy in stored samples of 12 752 ARIC Study participants, and followed them over a median of 19.7 years (1990-1992 to 2011) for the incidence of VTE (n = 537).
  
  
  RESULTS
  The seasonally adjusted 25(OH)D level was not associated with VTE incidence. In a model adjusted for age, race, sex, hormone replacement therapy, and body mass index, the hazard ratios of VTE across 25(OH)D quintiles 5 (high) to 1 (low) were: 1 (ref.), 0.84 (95% confidence interval [CI] 0.65-1.08), 0.88 (95% CI 0.68-1.13), 1.04 (95% CI 0.78-1.38), and 0.90 (95% CI 0.64-1.27). The lowest 25(OH)D quintile contained 59% African Americans, whereas the highest quintile contained 7% African Americans. However, lower 25(OH)D levels explained little of the 63% greater VTE risk of African Americans over whites in this cohort.
  
  
  CONCLUSIONS
  A low 25(OH)D level was not a risk factor for VTE in this prospective study. However, the totality of the literature (three studies) suggests that a low 25(OH)D level might modestly increase VTE risk in whites, but this needs further confirmation.
authors.affiliation: Division of Epidemiology & Community Health, School of Public Health, University of Minnesota, Minneapolis, MN, USA.
authors.forename: A R
authors.initials: AR
authors.lastname: Folsom
authors.forename: N S
authors.initials: NS
authors.lastname: Roetker
authors.forename: W D
authors.initials: WD
authors.lastname: Rosamond
authors.forename: S R
authors.initials: SR
authors.lastname: Heckbert
authors.forename: S
authors.initials: S
authors.lastname: Basu
authors.forename: M
authors.initials: M
authors.lastname: Cushman
authors.forename: P L
authors.initials: PL
authors.lastname: Lutsey
mesh_terms: D001741:Black or African American; D050197:Atherosclerosis / Q000097:blood* / Q000208:ethnology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D013058:Mass Spectrometry; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000097:blood* / Q000208:ethnology; D012307:Risk Factors; D012621:Seasons; D016896:Treatment Outcome; D014481:United States; D020246:Venous Thrombosis / Q000097:blood* / Q000208:ethnology; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: prospective studies; pulmonary embolism; risk factors; venous thrombosis; vitamin D