title: Blood 25-hydroxyvitamin D concentration and hypertension: a meta-analysis.
abstract: OBJECTIVE
  Increasing evidence indicates that vitamin D may influence the risk of hypertension, which is a major risk factor for cardiovascular disease. We conducted a meta-analysis to quantitatively review and summarize the results on the association between blood 25-hydroxyvitamin D concentrations and hypertension.
  
  
  METHODS
  Relevant studies were identified by a search of PubMed and EMBASE databases until November 2010. We also reviewed the references of retrieved articles. We included prospective and cross-sectional studies with blood 25-hydroxyvitamin D concentrations as the exposure and hypertension as the outcome. Studies had to report results as a relative risk or an odds ratio. We used random-effects model.
  
  
  RESULTS
  Of the 18 studies included in the meta-analysis, 4 were prospective studies and 14 were cross-sectional studies. The pooled odds ratio of hypertension was 0.73 [95% confidence interval (CI) 0.63-0.84] for the highest versus the lowest category of blood 25-hydroxyvitamin D concentration. In a dose-response meta-analysis, the odds ratio for a 40 nmol/l (16 ng/ml) (approximately 2 SDs) increment in blood 25-hydroxyvitamin D concentration was 0.84 (95% CI 0.78-0.90).
  
  
  CONCLUSIONS
  Findings from this meta-analysis indicate that blood 25-hydroxyvitamin D concentration is inversely associated with hypertension.
authors.affiliation: Institute of Environmental Medicine, Karolinska Institiute, Stockholm, Sweden. ann.burgaz@ki.se
authors.forename: Ann
authors.initials: A
authors.lastname: Burgaz
authors.forename: Nicola
authors.initials: N
authors.lastname: Orsini
authors.forename: Susanna C
authors.initials: SC
authors.lastname: Larsson
authors.forename: Alicja
authors.initials: A
authors.lastname: Wolk
mesh_terms: D003430:Cross-Sectional Studies; D006801:Humans; D006973:Hypertension / Q000097:blood*; D011446:Prospective Studies; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D