title: Vitamin D status and hypertensive disorders in pregnancy.
abstract: OBJECTIVE
  Several studies have reported increased risk of preeclampsia when 25-hyrdoxyvitamin D (25[OH]D) levels are low. The extent to which 25(OH)D may lower risk for hypertensive disorder during pregnancy remains unclear.
  
  
  METHODS
  Among women enrolled in the Project Viva prenatal cohort in Massachusetts, we examined associations of 25(OH)D levels obtained at 16.4-36.9 weeks of gestation (mean 27.9 weeks) with hypertensive disorders of pregnancy, including preeclampsia (56/1591, 3.5%) and gestational hypertension (109/1591, 6.9%).
  
  
  RESULTS
  We did not detect an association between plasma 25(OH)D concentration (mean 58, standard deviation 22 nmol/L) and preeclampsia. For each 25 nmol/L increase in 25(OH)D, the adjusted odds ratio for preeclampsia was 1.14 (95% confidence interval, 0.77-1.67). By contrast and contrary to hypothesis, higher 25(OH)D concentrations were associated with higher odds of gestational hypertension: adjusted odds ratio for gestational hypertension was 1.32 (95% confidence interval, 1.01-1.72) per each 25 nmol/L increment in 25(OH)D. Vitamin D intake patterns suggest that this association was not because of reverse causation. Although the elevated hypertension risk may be due to chance, randomized trials of vitamin D supplementation during pregnancy should monitor for gestational hypertension.
  
  
  CONCLUSIONS
  These data do not support the hypothesis that higher 25(OH)D levels lower the overall risk of hypertensive disorders of pregnancy.
authors.affiliation: Department of Neonatology, Beth Israel Deaconess Medical Center, Boston, MA; Division of Newborn Medicine, Boston Children's Hospital, MA; Harvard Medical School, Boston, MA. Electronic address: heburris@bidmc.harvard.edu.
authors.forename: Heather H
authors.initials: HH
authors.lastname: Burris
authors.affiliation: Obesity Prevention Program, Department of Population Medicine, Harvard Pilgrim Health Care Institute, Harvard Medical School, Boston, MA.
authors.forename: Sheryl L
authors.initials: SL
authors.lastname: Rifas-Shiman
authors.affiliation: Harvard Medical School, Boston, MA; Division of Gastroenterology and Nutrition, Boston Children's Hospital, MA.
authors.forename: Susanna Y
authors.initials: SY
authors.lastname: Huh
authors.affiliation: Harvard Medical School, Boston, MA; Obesity Prevention Program, Department of Population Medicine, Harvard Pilgrim Health Care Institute, Harvard Medical School, Boston, MA.
authors.forename: Ken
authors.initials: K
authors.lastname: Kleinman
authors.affiliation: Harvard Medical School, Boston, MA; Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA; Division of Pulmonary and Critical Care, Brigham and Women's Hospital, Boston, MA.
authors.forename: Augusto A
authors.initials: AA
authors.lastname: Litonjua
authors.affiliation: Harvard Medical School, Boston, MA; Obesity Prevention Program, Department of Population Medicine, Harvard Pilgrim Health Care Institute, Harvard Medical School, Boston, MA; Division of Women's Health, Department of Medicine, Brigham and Women's Hospital, Boston, MA.
authors.forename: Emily
authors.initials: E
authors.lastname: Oken
authors.affiliation: Harvard Medical School, Boston, MA; Division of Women's Health, Department of Medicine, Brigham and Women's Hospital, Boston, MA; Department of Epidemiology, Harvard School of Public Health, Boston, MA.
authors.forename: Janet W
authors.initials: JW
authors.lastname: Rich-Edwards
authors.affiliation: Harvard Medical School, Boston, MA; Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA; Department of Emergency Medicine, Massachusetts General Hospital, Boston.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Camargo
authors.affiliation: Harvard Medical School, Boston, MA; Obesity Prevention Program, Department of Population Medicine, Harvard Pilgrim Health Care Institute, Harvard Medical School, Boston, MA; Department of Nutrition, Harvard School of Public Health, Boston, MA.
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Gillman
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D046110:Hypertension, Pregnancy-Induced / Q000097:blood / Q000209:etiology* / Q000517:prevention & control; D016015:Logistic Models; D011247:Pregnancy; D011262:Pregnancy Trimester, Second / Q000097:blood; D011263:Pregnancy Trimester, Third / Q000097:blood; D011446:Prospective Studies; D012307:Risk Factors; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications* / Q000175:diagnosis
chemical_list: D015415:Biomarkers; D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: 25-Hydroxyvitamin D; Hypertension; Preeclampsia; Pregnancy; Pregnancy-induced; Vitamin D