title: Calcium intake and mortality from all causes, cancer, and cardiovascular disease: the Cancer Prevention Study II Nutrition Cohort.
abstract: BACKGROUND
  Calcium intake may be important for bone health, but its effects on other outcomes, including cardiovascular disease (CVD) and cancer, remain unclear. Recent reports of adverse cardiovascular effects of supplemental calcium have raised concerns.
  
  
  OBJECTIVE
  We investigated associations of supplemental, dietary, and total calcium intakes with all-cause, CVD-specific, and cancer-specific mortality in a large, prospective cohort.
  
  
  METHODS
  A total of 132,823 participants in the Cancer Prevention Study II Nutrition Cohort, who were followed from baseline (1992 or 1993) through 2012 for mortality outcomes, were included in the analysis. Dietary and supplemental calcium information was first collected at baseline and updated in 1999 and 2003. Multivariable-adjusted Cox proportional hazards models with cumulative updating of exposures were used to calculate RRs and 95% CIs for associations between calcium intake and mortality.
  
  
  RESULTS
  During a mean follow-up of 17.5 y, 43,186 deaths occurred. For men, supplemental calcium intake was overall not associated with mortality outcomes (P-trend > 0.05 for all), but men who were taking ≥1000 mg supplemental calcium/d had a higher risk of all-cause mortality (RR: 1.17; 95% CI: 1.03, 1.33), which was primarily attributed to borderline statistically significant higher risk of CVD-specific mortality (RR: 1.22; 95% CI: 0.99, 1.51). For women, supplemental calcium was inversely associated with mortality from all causes [RR (95% CI): 0.90 (0.87, 0.94), 0.84 (0.80, 0.88), and 0.93 (0.87, 0.99) for intakes of 0.1 to <500, 500 to <1000, and ≥1000 mg/d, respectively; P-trend < 0.01]. Total calcium intake was inversely associated with mortality in women (P-trend < 0.01) but not in men; dietary calcium was not associated with all-cause mortality in either sex.
  
  
  CONCLUSIONS
  In this cohort, associations of calcium intake and mortality varied by sex. For women, total and supplemental calcium intakes are associated with lower mortality, whereas for men, supplemental calcium intake ≥1000 mg/d may be associated with higher all-cause and CVD-specific mortality.
authors: Epidemiology Research Program, American Cancer Society, Atlanta, GA; and Department of Epidemiology, Rollins School of Public Health, Laney Graduate School, and.
authors: Baiyu
authors: B
authors: Yang
authors: Epidemiology Research Program, American Cancer Society, Atlanta, GA; and.
authors: Peter T
authors: PT
authors: Campbell
authors: Epidemiology Research Program, American Cancer Society, Atlanta, GA; and.
authors: Susan M
authors: SM
authors: Gapstur
authors: Epidemiology Research Program, American Cancer Society, Atlanta, GA; and.
authors: Eric J
authors: EJ
authors: Jacobs
authors: Department of Epidemiology, Rollins School of Public Health, Winship Cancer Institute, Emory University, Atlanta, GA.
authors: Roberd M
authors: RM
authors: Bostick
authors: Department of Epidemiology, Rollins School of Public Health, Winship Cancer Institute, Emory University, Atlanta, GA.
authors: Veronika
authors: V
authors: Fedirko
authors: Department of Epidemiology, Rollins School of Public Health, Winship Cancer Institute, Emory University, Atlanta, GA.
authors: W Dana
authors: WD
authors: Flanders
authors: Epidemiology Research Program, American Cancer Society, Atlanta, GA; and marji.mccullough@cancer.org.
authors: Marjorie L
authors: ML
authors: McCullough
mesh_terms: D000328:Adult; D000368:Aged; D002136:Calcium, Dietary / Q000009:adverse effects*; D002318:Cardiovascular Diseases / Q000401:mortality*; D002423:Cause of Death; D015331:Cohort Studies; D019587:Dietary Supplements / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000401:mortality*; D016016:Proportional Hazards Models; D012307:Risk Factors; D012737:Sex Factors
chemical_list: D002136:Calcium, Dietary
keywords: all-cause mortality; calcium intake; cardiovascular disease mortality; cohort study; dietary supplements