It has always been my practice to make sure women take their daily calcium supplements to prevent osteoporosis. It is my contention that by building bone the right way and preventing a fracture is very important health issue. It is recommended by diffirent medical societies that calcium supplements be given between 1000- 1200 mg per day.
Now comes a new study showing proofs that calcium supplements may not be that safe after all. A study published in BMJ in JUly 2010 with a reanalysis done in 2011 showed that calcium supplementation should be reviewed due to inherent harm.
To investigate whether calcium supplements increase the risk of cardiovascular events.
Patient level and trial level meta-analyses.
Medline, Embase, and Cochrane Central Register of Controlled Trials (1966-March 2010), reference lists of meta-analyses of calcium supplements, and two clinical trial registries. Initial searches were carried out in November 2007, with electronic database searches repeated in March 2010.
Eligible studies were randomised, placebo controlled trials of calcium supplements (>or=500 mg/day), with 100 or more participants of mean age more than 40 years and study duration more than one year. The lead authors of eligible trials supplied data. Cardiovascular outcomes were obtained from self reports, hospital admissions, and death certificates.
15 trials were eligible for inclusion, five with patient level data (8151 participants, median follow-up 3.6 years, interquartile range 2.7-4.3 years) and 11 with trial level data (11 921 participants, mean duration 4.0 years). In the five studies contributing patient level data, 143 people allocated to calcium had a myocardial infarction compared with 111 allocated to placebo (hazard ratio 1.31, 95% confidence interval 1.02 to 1.67, P=0.035). Non-significant increases occurred in the incidence of stroke (1.20, 0.96 to 1.50, P=0.11), the composite end point of myocardial infarction, stroke, or sudden death (1.18, 1.00 to 1.39, P=0.057), and death (1.09, 0.96 to 1.23, P=0.18). The meta-analysis of trial level data showed similar results: 296 people had a myocardial infarction (166 allocated to calcium, 130 to placebo), with an increased incidence of myocardial infarction in those allocated to calcium (pooled relative risk 1.27, 95% confidence interval 1.01 to 1.59, P=0.038).
Calcium supplements (without coadministered vitamin D) are associated with an increased risk of myocardial infarction. As calcium supplements are widely used these modest increases in risk of cardiovascular disease might translate into a large burden of disease in the population. A reassessment of the role of calcium supplements in the management of osteoporosis is warranted.
The reanalysis of this study done recently and published in the same journal showed that the risk of MI is actualy MODEST at best around 20% for MI and 30% for stroke BUT… considering the huge number of women doctors have been recommending to take calcium supplements… justify a further close look at this practice as this will have enormous impact on health care risk.
For the past year…I have not been recommending calcium supplements to my patients especially my diabetic hypertensive patients. I make sure that my dietitian supplements their diet with enough calcium sources from food and milk. If need be, those patients who cant take enough from food are the ones given the supplements but this number is becoming less each day.
If you are taking calcium supplements on your own , my recommendation is to stop. If you are taking the supplements as part of your osteoporosis program then talk to your doctor first before stopping.