title: A prospective cohort study of Vitamins B, C, E, and multivitamin intake and endometriosis.
abstract: OBJECTIVE
  Diet is a potentially modifiable risk factor for endometriosis. It has been hypothesized that vitamins C, E, and the B vitamins may influence factors involved in the pathogenesis of endometriosis, such as oxidative stress and steroid hormone metabolism. In this large, prospective cohort study, we examined the relation between intake of vitamins C, E, the B vitamins, and the use of multivitamin supplements and diagnosis of endometriosis.
  
  
  METHODS
  Data were collected from women in the Nurses' Health Study II between 1991 and 2005. Diet was assessed via food frequency questionnaire. Incidence rate ratios (RR) and 95% confidence intervals (CI) were estimated using time-varying Cox proportional hazards models.
  
  
  RESULTS
  A total of 1383 incident cases of laparoscopically-confirmed endometriosis were observed among 70,617 women during 735,286 person years of follow-up. Intakes of thiamine (B1) (RR = 0.84, CI = 0.72-0.99; P-value, test for linear trend [P] = 0.04), folate (B9) (RR = 0.79, CI = 0.66-0.93; P = 0.003), vitamin C (RR = 0.81, CI = 0.68-0.95; P = 0.02), and vitamin E (RR = 0.70, CI = 0.59-0.83; P<0.0001) solely from food sources were inversely related to endometriosis diagnosis. However, intakes of these nutrients from supplements alone were unrelated to endometriosis.
  
  
  CONCLUSIONS
  Thiamine, folate, vitamin C, and vitamin E from food sources are inversely related to endometriosis risk. Our results suggest that the protective mechanism may not be related to the nutrients themselves but rather other components of foods rich in these micronutrients or factors correlated with diets high in these vitamin-rich foods.
authors: Department of Nutrition, Harvard School of Public Health, Boston, MA - USA.
authors: Anne Marie
authors: AM
authors: Darling
authors: Department of Nutrition, Harvard School of Public Health, Boston, MA - USA ; Department of Epidemiology, Harvard School of Public Health, Boston, MA - USA ; Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA - USA.
authors: Jorge E
authors: JE
authors: Chavarro
authors: Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA - USA.
authors: Susan
authors: S
authors: Malspeis
authors: Department of Obstetrics, Gynecology, and Reproductive Biology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA - USA ; Division of Nutritional Epidemiology, The National Institute for Environmental Medicine, Karolinska Institutet, Stockholm - Sweden.
authors: Holly R
authors: HR
authors: Harris
authors: Department of Epidemiology, Harvard School of Public Health, Boston, MA - USA ; Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA - USA ; Department of Obstetrics, Gynecology, and Reproductive Biology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA - USA.
authors: Stacey A
authors: SA
authors: Missmer
keywords: B vitamins; Diet; Endometriosis; Multivitamins; Prospective cohort; Vitamin C; Vitamin E