title: Vitamin C and the risk of preeclampsia--results from dietary questionnaire and plasma assay.
abstract: BACKGROUND
  Oxidative stress plays an important role in the pathophysiology of preeclampsia.
  
  
  METHODS
  In a case-control study of 109 women with preeclampsia and 259 controls, maternal dietary and plasma vitamin C in relation to preeclampsia risk were assessed. Dietary intake during the periconceptional period and pregnancy was ascertained using a semiquantitative food frequency questionnaire. Logistic regression procedures were used to derive odds ratios (OR) and 95% confidence intervals (CI). Plasma ascorbic acid was determined using automated enzymatic procedures.
  
  
  RESULTS
  After adjusting for maternal age, parity, prepregnancy body mass index, and energy intake, women who consumed <85 mg of vitamin C daily (below the recommended dietary allowance), as compared with others, experienced a doubling in preeclampsia risk (OR = 2.1; 95% CI = 1.1-3.9). The OR for extreme quartiles of plasma ascorbic acid (<42.5 vs > or = 63.3 micromol/liter) was 2.3 (95% CI = 1.1-4.6). Compared with women in the highest quartile, those with plasma ascorbic acid <34.6 micromol/liter (lowest decile) experienced a 3.8-fold increased risk of preeclampsia (95% CI = 1.7-8.8).
  
  
  CONCLUSIONS
  Our results, if confirmed, would suggest that current public health efforts to increase intake of fruits and vegetables rich in vitamin C and other antioxidants may reduce the risk of preeclampsia.
authors.affiliation: Department of Epidemiology, University of Washington School of Public Health and Community Medicine, 1959 NE Pacific Avenue, Seattle, WA 98195, USA. clinn@u.washington.edu
authors.forename: Cuilin
authors.initials: C
authors.lastname: Zhang
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Williams
authors.forename: Irena B
authors.initials: IB
authors.lastname: King
authors.forename: Edward E
authors.initials: EE
authors.lastname: Dashow
authors.forename: Tanya K
authors.initials: TK
authors.lastname: Sorensen
authors.forename: Ihunnaya O
authors.initials: IO
authors.lastname: Frederick
authors.forename: Mary Lou
authors.initials: ML
authors.lastname: Thompson
authors.forename: David A
authors.initials: DA
authors.lastname: Luthy
mesh_terms: D000293:Adolescent; D000328:Adult; D001205:Ascorbic Acid / Q000008:administration & dosage* / Q000097:blood*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D011225:Pre-Eclampsia / Q000097:blood* / Q000503:physiopathology* / Q000517:prevention & control; D011247:Pregnancy; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014861:Washington / Q000453:epidemiology
chemical_list: D001205:Ascorbic Acid