Letters Calcium and heart attacks

No evidence for increased risk

BMJ 2010; 341 doi: http://dx.doi.org/10.1136/bmj.c4995 (Published 15 September 2010) Cite this as: BMJ 2010;341:c4995
  1. Gerardo Heiss, professor1,
  2. Judith Hsia,
  3. Mary Pettinger,
  4. Barbara V Howard,
  5. Garnet Anderson
  1. 1School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7400, USA
  1. gerardo_heiss{at}unc.edu

    Bolland and colleagues contrast the results of their meta-analysis with those of the women’s health initiative (WHI) randomised controlled trial of calcium/vitamin D supplementation with 254 000 subject years of follow-up.1 2 Cardiovascular events in the WHI study were pre-specified end points classified by centrally trained adjudicators on the basis of medical record review. Its finding that calcium/vitamin D had no effect on risk of subsequent myocardial infarction was supported by prospectively collected, adjudicated data for coronary revascularisation, admission for angina, stroke, and transient ischaemic attack.

    Bolland and colleagues suggest a subgroup analysis of the WHI data on participants who most resemble those with observations in their analyses.1 The 1400 WHI participants in the calcium/vitamin D trial aged 70-79 with a body mass index of <30 and a total daily calcium intake <800 mg experienced 64 incident myocardial infarctions and 89 coronary heart disease events (myocardial infarction or death from coronary heart disease); hazard ratios compared with placebo were 0.90 (95% confidence interval 0.55 to 1.48; P=0.68) and 0.94 (0.62 to 1.43; P=0.78) respectively. There were no trends with leanness or age. Additional, detailed subgroup analyses show no evidence of increased risk for coronary heart disease events with calcium supplementation.2

    Notes

    Cite this as: BMJ 2010;341:c4995

    Footnotes

    • Competing interests: None declared.

    References