free full access: Calcium supplements with/without vitamin D and risk of cardiovascular events: reanalysis of the Women’s Health Initiative - bmj.com (including responses)

Abstract/Conclusions:
Calcium supplements with or without vitamin D modestly increase the risk of cardiovascular events, especially myocardial infarction, a finding obscured in the WHI CaD Study by the widespread use of personal calcium supplements. A reassessment of the role of calcium supplements in osteoporosis management is warranted.

excerpt (from full text):

"...An important question that arises is whether co-administered calcium and vitamin D affects cardiovascular risk. The Women’s Health Initiative reported no adverse effect of calcium and vitamin D (1 g calcium/400 IU vitamin D daily) on any cardiovascular end point in their large (n=36 282), seven year, randomised, placebo controlled trial.3 4 However, 54% of the participants were taking personal (non-protocol) calcium supplements at randomisation and 47% were taking personal vitamin D supplements, effectively rendering this trial a comparison of higher dose and lower dose calcium and vitamin D for most of the participants.

Allowing clinical trial participants free access to the intervention being studied is unusual and has the potential to obscure both adverse and beneficial effects..."

What is already known on this topic

• A recent meta-analysis suggested that calcium supplements taken without vitamin D increase the risk of myocardial infarction
• The Women’s Health Initiative reported no effect of calcium and vitamin D supplements on cardiovascular events, but most of the participants were taking personal, non-protocol calcium supplements at study entry

What this study adds

• Re-analysis of the Women’s Health Initiative data shows women allocated to calcium and vitamin D administration who were not taking personal calcium supplements were at increased risk of cardiovascular events
• Meta-analyses of trials involving 29 000 people found that calcium supplements used with or without vitamin D modestly increase cardiovascular risk, suggesting their use in osteoporosis management should be reassessed
  
  

  Relevant Articles:

  Editorial: Do calcium plus vitamin D supplements increase cardiovascular risk?
  
  • Bo Abrahamsen,
  • Opinder Sahota
  BMJ 2011;342:doi:10.1136/bmj.d2080 (Published 19 April 2011)
  • [Extract]
  • [Full text]
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  Rapid responses to this article

  • Guideline for calcium supplement is required
    

    • Gauranga C. Dhar

    BMJ 21 April 2011
    • [Full text]
  • Insufficient evidence
    

    • Peter D Burrill

    BMJ 21 April 2011
    • [Full text]
  • Bicarbonate or Citrate?
    

    • Gary F. Pesowski

    BMJ 20 April 2011
    • [Full text]

  
  

  Relevant Articles

  • Research: Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis
    

    • Mark J Bolland,
    • Alison Avenell,
    • John A Baron,
    • Andrew Grey,
    • Graeme S MacLennan,
    • Greg D Gamble,
    • Ian R Reid

    BMJ 2010;341:doi:10.1136/bmj.c3691 (Published 29 July 2010)
    • [Abstract]
    • [Full text]
    • [PDF]
  • Research: Vascular events in healthy older women receiving calcium supplementation: randomised controlled trial
    

    • Mark J Bolland,
    • P Alan Barber,
    • Robert N Doughty,
    • Barbara Mason,
    • Anne Horne,
    • Ruth Ames,
    • Gregory D Gamble,
    • Andrew Grey,
    • Ian R Reid

    BMJ 2008;336:262 doi:10.1136/bmj.39440.525752.BE (Published 15 January 2008)
    • [Abstract]
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    • [Abridged PDF]

  This article has been cited by other articles:

  • Do calcium plus vitamin D supplements increase cardiovascular risk? BMJ 2011;342:d2080
    • [Full text]
    • [PDF]