For years, doctors (including me!) had been telling their patients (especially postmenopausal women over 60 and older men) to take calcium supplements to prevent risks of osteoporosis.  Now, with recent research findings, many doctors are holding off on telling our patients to take calcium supplements.  Perhaps you routinely take calcium supplements as well.  If so, you should know what this new research has shown and why you might want to stop taking your calcium supplements.

Calcium Supplements Linked to Heart Attack Risk

That was the headline of a recent ABC World News Report back in May this year (2012), heralding the bottom line finding of a recent study by German and Swiss researchers.  Needless to say, my phone was buzzing the next day from patients who’ve routinely been taking calcium supplements.  A similar prior study done a few years earlier out of the University of Auckland, New Zealand [Calcium Supplements May Increase Heart Attack Risk in Older Women, British Medical Journal, January 2008] had reached the same conclusion in studying a small group of women over 55.  In medical research though, the findings of one study isn’t always the definitive answer. But now there were two different studies with the same conclusion.

However, prior research had also suggested that higher intakes of calcium could lower blood pressure and prevent type 2 diabetes – two major risks for developing heart disease. As I keep an open mind towards new research that better protects my patients’ health, I investigated further into this new research.

The latest findings are based on a study done out of one of the German branches of the European Prospective Investigation into Cancer and Nutrition (EPIC) in Heidelberg, Germany.  The study followed 24,000 participants aged 35 to 64 for 11 years.  Their diets for the preceding 12 months were evaluated and all participants were asked if they took vitamin or mineral supplements.  During the study period, there were 354 heart attacks, 260 strokes, and 267 associated deaths.

Of those participants who took calcium supplements regularly, they were found to be 86% more likely to have a heart attack than those who didn’t.  In addition, the participants who took only calcium supplements for their calcium intake were more than twice as likely to have a heart attack.  The researchers bottom line conclusion was that while calcium intake from diet might not give significant cardiovascular benefits, calcium supplements may raise heart attack risk and should be taken with caution.

Further, two other researchers from the University of Auckland, New Zealand, Drs. Ian Reid and Mark Bolland, in an accompanying editorial to the study commented that ‘the safety of calcium supplements are coming under scrutiny now.’ These safety factors include kidney stones, gut and abdominal symptoms.  They also commented that even though prior research had indicated that calcium supplements may cut risk factors for cardiovascular disease (type 2 diabetes, blood pressure), those findings didn’t necessarily mean less risk of heart attack or stroke.

The problem is that getting calcium from your food is much different from getting calcium from supplements.  Dietary calcium is taken in smaller amounts throughout the day so it is absorbed more slowly.  Taking 1200 mg at a time in a supplement causes calcium flooding in the blood.  Apparently, it is soaring calcium blood spikes that present the problem as supplemental calcium does not give the same metabolic effect as dietary calcium. The researchers conclusion was:   ‘calcium supplements were neither safe or effective and should be discouraged.’

So there you have it.  You may wonder, as I did, if calcium flooding is the problem from taking the calcium all at once, would it be safer to divide the 1200 mg into smaller doses throughout the day?  Also, did the type of calcium supplement matter? What about the smaller amounts of calcium contained in multivitamin and mineral supplements? What about people with medical conditions who rely on supplements? For sure, these studies pose a lot more questions.

My Recommendations to You

As I always like to err on the side of safety and caution, I am now recommending the following to my patients and readers:

• If you are a postmenopausal woman, or man over 60, of normal health, and were using individual calcium supplements as prevention against osteoporosis, you can get your calcium needs from your food alone. The National Institute of Health recommends 1200 mg of calcium a day for this age group.  I also recommend that you get baseline calcium (and Vitamin D) levels done and repeat these levels periodically. Recent research shows that Vitamin D and magnesium deficiencies, and perhaps too high vitamin A levels, may be the real culprits behind osteoporosis. Your body needs magnesium and Vitamin D to absorb calcium correctly.  Also, adequate vitamin K levels can prevent fractures as well.

• If you have parathyroid hormone issues, osteoporosis, or some other calcium-dependent condition, talk to your doctor about the latest research findings and what level of calcium supplementation is safest for you.

• Remember, dairy is not the only good dietary source of calcium.  Almond milk contains just slightly less calcium than cow’s milk. Vegetables like kale, spinach, broccoli contain good levels of calcium, as do other foods like salmon and enriched cereals.

• If you take a multiple vitamin or mineral supplement for nutritional insurance, balance the amount of calcium in it (not more than 35% of your daily needs) with foods you eat.

As it stands, I feel that several different pieces of research now point to the risk of taking individual calcium supplements – especially in older women.  Until we have more answers to all the questions that these studies pose, it may be safer to stay away from calcium supplements.  I also encourage you to explore this subject and your concerns with your doctor.

Stay Well,
Mark Rosenberg, M.D.
Natural Health News

Calcium supplements may increase heart attack risk in older women, http://www.sciencedaily.com/releases/2008/01/080116193102.htm

Calcium supplements linked to significantly increased heart attack risk, http://www.sciencedaily.com/releases/2012/05/120523200752.htm

Calcium supplements limked to heart attack risk, http://abcnews.go.com/Health/HeartHealth/calcium-supplements-linked-heart-attack-risk/story?id=16413252