Many people who take corticosteroids for inflammatory forms of arthritis also take calcium supplements to prevent bone loss and fracture. But there is evidence the supplements can increase risk of heart attack and stroke, according to a study released online April 19 in the BMJ.
“The study suggests that calcium supplements do more harm in the form of heart attacks and strokes than they do good in the form of fractures prevented,” says lead author Ian Reid, MD, professor of medicine and endocrinology at the University of Auckland in New Zealand.
"We should get calcium from food, as dietary calcium does not appear to increase the risk of heart disease," he adds.
The evidence raises questions for millions of older women who take calcium supplements to keep bones strong and help ward off osteoporosis. And it may be of particular concern for those on corticosteroids, which decrease absorption of calcium by the intestines while increasing excretion of calcium through the kidneys.
Dr. Reid and other medical experts agree it’s important to talk to your doctor about your specific calcium needs, what supplements you take – for instance, if you take a multivitamin and a calcium supplement – and what your diet generally includes. These factors can impact your doctor’s recommendation.
What the Studies Show
In 2007, researchers from the Women's Health Initiative Calcium/Vitamin D Supplementation trial reported no increase in heart risks associated with calcium supplements among more than 36,000 women followed for seven years. But more than half of the women in the study were taking calcium supplements on their own before the trial began, which might have masked the findings.
So Dr. Reid and colleagues looked only at the subset of 16,718 women who had not been taking supplements at the start of the trial. Results showed that among this group, those assigned to take calcium and vitamin D had a 13 to 22 percent higher risk of heart attack and stroke. Women taking placebo had no increase in risk.
Further analyses that incorporated data from 13 other trials involving a total of about 29,000 women showed consistent findings. Overall, women taking supplements were at about 25 to 30 percent increased risk for heart attack and 15 to 20 percent increased risk for stroke.
"In our analysis, treating 1,000 patients with calcium or calcium and vitamin D for five years would cause an additional six [heart attacks] or strokes and prevent only three fractures," Dr. Reid says.
The researchers hypothesize that the sudden spike in blood calcium levels when starting a supplement causes a lying down of calcium in the artery walls that leads to hardening of the arteries, a major cause of heart attack and stroke.
To question is a good thing. However a sample size of over 16,000 is very strong data indeed. Having taught Statistics at the college level I always look at the sample size and any extraneous variables. Dr. Reid's study looks very strong and I note that he viewed other studies involving 13,000 more individuals.
I currently work as a trainer and most of my clients have had past injuries and pain including myself. Working out in a pool has been a favorite way for me when recovering from ACL surgery. I have found that the worst thing to do is no exercise at all. I have also worked with people over age 75 doing exercises from a chair. All of us are unique individuals and benefit from varying degrees and different types of exercise.
Back to supplements for a minute, keep in mind it is a multi million dollar industry and all of us would like to think that there are no side effects to anything that we are taking.
Final thought, one could pull the actual studies and look at them closer if desired.
I have been taking calcium since I was 40.
I do have RA and I was treated with Prednison for about 2 yrs. 2 yrs ago I had a Bone densi ty scan about that time a had Ostopia.
My new Rheumatologist order Reclast and my new Scan show a very good improvement and I will now stop for a yr.
I take Rituxan for my RA twice a yr.
I am not overweight and eat healthy but I do believe in vitamins. I was very healthy until I was 72 yrs. when I developed RA.
I am not diabetic, no high blood pressure or Cloresterol.
Should I stop taking calcium?
I question anything that comes in a scientific claim.
We need to consider the variables in the study and the alternatives available to people whose osteoarthritis prevents exercise.
I am 57 and have slight osteoarthritis and did not supplement calcium when recommended by my doctor years ago. I requested a blood profile to see if I was deficient which I was not. Weight bearing exercise and proper nutrition I believe are still the best ways to increase bone density. I question anything that comes in a bottle prescription or not.
http://www.knowguff.com/2011/04/do-calcium-supplements-cause-heart.html
http://www.knowguff.com/2011/04/warfarin-vitamin-k-and-calcium.html
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