title: Serum vitamin D level and prehypertension among subjects free of hypertension.
abstract: BACKGROUND
  Low serum vitamin D levels are associated with high blood pressure (BP). Prehypertension is a preclinical stage where primary prevention efforts have been recommended for delaying or preventing the onset of hypertension. However, the majority of studies examining the association between vitamin D and BP have not accounted for kidney function or systemic inflammation.
  
  
  METHODS
  Participants of the 3rd National Health and Nutrition Examination Survey > 20 years of age and free of hypertension (n = 9,215, 53.5% women) and clinical cardiovascular disease were examined. Serum vitamin D levels were analyzed as quartiles. Prehypertension (n = 3,712) was defined as systolic BP 120-139 mm Hg or diastolic BP 80-89 mm Hg.
  
  
  RESULTS
  Lower serum vitamin D levels were found to be associated with prehypertension independent of potential confounders including body mass index (BMI), serum cholesterol, C-reactive protein and estimated glomerular filtration rate. Compared to the highest quartile of serum vitamin D (referent), the odds ratio (95% confidence interval) of prehypertension associated with the lowest quartile was 1.48 (1.16-1.90; p trend < 0.0001). This association persisted in subgroup analyses by gender, race-ethnicity and BMI.
  
  
  CONCLUSIONS
  Lower serum vitamin D levels are associated with prehypertension in a representative sample of US adults.
authors.affiliation: Department of Community Medicine, West Virginia University School of Medicine, Morgantown, W. Va. 26506-9190, USA.
authors.forename: Charumathi
authors.initials: C
authors.lastname: Sabanayagam
authors.forename: Anoop
authors.initials: A
authors.lastname: Shankar
authors.forename: Shanmugasundaram
authors.initials: S
authors.lastname: Somasundaram
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000378:metabolism; D002784:Cholesterol / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D008297:Male; D009749:Nutrition Surveys; D058246:Prehypertension / Q000097:blood* / Q000453:epidemiology*; D015995:Prevalence; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D014807:Vitamin D / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood* / Q000453:epidemiology*
chemical_list: D014807:Vitamin D; D002097:C-Reactive Protein; D002784:Cholesterol