title: Calcium intake and lung cancer risk among female nonsmokers: a report from the Shanghai Women's Health Study.
abstract: BACKGROUND
  Calcium has been implicated in carcinogenesis and linked to the risk of several cancers in epidemiologic studies; however, few studies have investigated the association of calcium intake with lung cancer risk, particularly among nonsmokers.
  
  
  METHODS
  We evaluated the association of intakes of calcium and related minerals, assessed through a food frequency questionnaire, with lung cancer risk among 71,267 female nonsmokers who were cancer free at baseline in the Shanghai Women's Health Study, a population-based, prospective cohort study. Multivariate Cox regression was used to calculate hazard ratios (HR) and 95% confidence intervals (CI).
  
  
  RESULTS
  During follow-up through December 2009 (median follow-up time: 11.2 years), 428 incident lung cancer cases accrued. The median intakes of dietary calcium, magnesium, and phosphorus were 441, 266, and 935 mg/d, respectively. Intakes of calcium, phosphorus, and the calcium-to-magnesium (Ca:Mg) ratio were inversely associated with lung cancer risk. The corresponding HRs (95% CIs) for the highest compared with the lowest quartile were 0.66 (0.48, 0.91) for calcium, 0.55 (0.36, 0.85) for phosphorus, and 0.62 (0.47, 0.82) for the Ca:Mg ratio. No association was observed for dietary magnesium intake or the use of calcium- or vitamin D-containing supplements.
  
  
  CONCLUSIONS
  Our study provides some of the first evidence suggesting a possible role for increasing dietary calcium intake in lung cancer prevention among female nonsmokers, especially in populations with relatively low calcium intake.
authors.affiliation: Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN 37203, USA.
authors.forename: Yumie
authors.initials: Y
authors.lastname: Takata
authors.forename: Xiao-Ou
authors.initials: XO
authors.lastname: Shu
authors.forename: Gong
authors.initials: G
authors.lastname: Yang
authors.forename: Honglan
authors.initials: H
authors.lastname: Li
authors.forename: Qi
authors.initials: Q
authors.lastname: Dai
authors.forename: Jing
authors.initials: J
authors.lastname: Gao
authors.forename: Qiuyin
authors.initials: Q
authors.lastname: Cai
authors.forename: Yu-Tang
authors.initials: YT
authors.lastname: Gao
authors.forename: Wei
authors.initials: W
authors.lastname: Zheng
mesh_terms: D017677:Age Distribution; D000368:Aged; D002136:Calcium, Dietary / Q000008:administration & dosage*; D002681:China / Q000453:epidemiology; D015331:Cohort Studies; D016001:Confidence Intervals; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000453:epidemiology* / Q000517:prevention & control*; D008875:Middle Aged; D008903:Minerals / Q000008:administration & dosage; D015999:Multivariate Analysis; D015995:Prevalence; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D012907:Smoking; D015996:Survival Rate; D016387:Women's Health
chemical_list: D002136:Calcium, Dietary; D008903:Minerals