A week ago we sent out a health alert about the dangers of calcium supplements for men. That was because of an article in JAMA Internal Medicine (online, February, 4, 2013) reporting that men taking more than 1500 mg of calcium daily in the form of supplements were at increased risk for cardiovascular disease death. The size of the study (over 200,000 men) and the length of the follow-up (12 years) suggested that this was unlikely to be due to chance.
There was one confusing result, however. The women who participated in this National Institutes of Health-AARP Diet and Health Study were NOT at increased risk for death. The nearly 170,000 women who were included in the research seemed to avoid the small but significant risk that calcium seemed to pose for men. The authors concluded:
“We found a significant interaction by sex. Elevated CVD [cardiovascular disease] mortality with increasing supplemental calcium in-take was observed only in men; however, we cannot rule out the possibility that supplemental calcium intake may be associated with cardiovascular mortality in women.”
Now, a brand new study published in the BMJ (online, February 13, 2013) suggests that women may indeed be vulnerable to complications from high doses of calcium in supplements. The Swedish government has been tracking the health of all its residents since 1952. In this most recent research, investigators analyzed data from 61,443 Swedish women who were followed for an average of 19 years. (They were born between 1914 and 1948.)
Over the nearly two decades they were tracked, about 12,000 women died (17%). One third of the deaths were attributed to cardiovascular disease. Now here’s where it gets interesting. Women who consumed more than 1,400 mg of calcium from their diets had a higher risk of cardiovascular disease mortality (about 50% greater) than women who consumed 600 to 1000 mg of calcium from their food. If you add in calcium supplements (as pills) on top of dietary calcium (from food), however, the risk jumps dramatically. In their own words:
“Women who had a high dietary intake of calcium exceeding 1400 mg/day and additionally used calcium supplements had a higher mortality rate than women with a similarly high intake of calcium but without taking supplements. Thus, among calcium tablet users (500 mg calcium per tablet), a high dietary calcium intake (>1400 mg/day) conferred a multivariable adjusted hazard ratio of 2.57 for all cause mortality compared with a dietary calcium intake of between 600 and 999 mg/day.”
In the world of epidemiology, a greater than two-fold increased risk of death is considered serious and not likely to be caused by chance. Add this study to other research and a pattern starts to emerge.
• A study last spring involving nearly 24,000 German adults found that those taking calcium supplements were more likely to have heart attacks during the 11 years of follow-up (Heart, online May 23, 2012).
A study of American women from the Women’s Health Initiative (WHI) involved 16,000 women over the age of 40. Those who were randomized to receive calcium and vitamin D (vs. placebo) were about 20% more likely to experience heart attacks or other vascular problems.
Speaking of vitamin D, many women have assumed that vitamin D would somehow protect them from the problems of too much calcium. Here is what the Swedish investigators found:
“Vitamin D intake did not significantly modify the associations between calcium intake and the rate of deaths from all causes, cardiovascular disease, or ischaemic heart disease.”
That said, the Swedish researchers propose that too much calcium in the diet plus supplemental calcium pills could suppress vitamin D levels, and lead to inflammation and hypertension as well as elevated triglycerides, hardening of arteries and atherosclerosis. They also suggest that too much calcium in the blood can increase the risk of clots due to a “hypercoagulable state.” Other researchers have also proposed that excess calcium might increase blood coagulation and lead to “stiffness” in the arterial wall. They have also proposed that:
“One plausible biological mechanism through which calcium may exert a harmful effect on cardiovascular health is vascular calcification–the deposit of calcium phosphate in cardiovascular structures…Emerging evidence has linked calcification of coronary arteries with increased atherosclerotic plaque burden, risk of coronary heart disease and mortality.”
BOTTOM LINE:
Although calcium is crucial for good health, the body is well equipped to regulate levels of this essential element. For reasons that are not entirely clear, many health professionals hopped on the calcium bandwagon and started recommending very high doses in the form of pills. Commercials on TV also encouraged women to take extra calcium. It is not unusual for a woman to be told to take 1000 mg or more of elemental calcium on top of dairy products and other foods high in calcium. At last count nearly two-thirds of American women take calcium supplements.
Based on several recent studies and the most recent Swedish research, it would appear that this advice might well have been misguided. When women consume lots of calcium from their diets and add calcium supplements to that, there is a significant increase in the risk of cardiovascular death.
So, what’s a woman to do, given all the conflicting information of the last several decades? The Swedish researchers did NOT find any increased risk of death when daily dietary calcium intake ranged between 600 mg and 1,400 mg. That could well be the sweet spot. A glass of milk, a carton of low-fat (unsweetened) yogurt and lots of dark green leafy vegetables are likely to accomplish this goal. From where we sit, getting a moderate amount of calcium from food makes a lot of sense. Basically, we’re back to grandma’s wisdom: moderation in all things!
We welcome your comments below. Here are some that were posted to a previous link.

Twenty years ago at age 52, I decided to take calcium because of the bone loss associated with menopause. After several months, I developed large, painful, palpable lumps on my Achilles tendons making it painful to walk. My Dr. sent me to an arthritis clinic at a nearby teaching hospital. The first diagnoses was anklyosing spondolythyasis which was disproved with further blood work.
It took over a year to find out the lumps which were appearing around other joints by this time, were caused from taking calcium. This was not discovered by a Dr., but by accident in an article in a medical journal. The lumps disappeared in a couple of months when the calcium was stopped. The body does not seem to like the addition of minerals not ingested from food.

DB
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This situation is very confusing. What to do? What to do? Would you please do a program very soon devoted to the subject of calcium. My bone density is below what it should be. I stopped Foxamax because of its side effects and have been taking calcium regularly. Is it possible to get all the calcium we need from our diet? Thanks.
Mary
PEOPLE’S PHARMACY RESPONSE: You may be interested in a show we did a couple of years ago on Bone Vitality.
++++++++++++++++++
It’s great to see someone shedding light on health issues related to calcium supplements. Several years ago, a family member was suffering from kidney stones, and her doctor suggested that they were caused by too much calcium. That’s what prompted me to do extensive research into nutritional supplements. There’s no doubt in my mind that the best source of calcium is good old-fashioned food.
M.A.L.
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  1. Beulah S.
    Reply

    I too stopped taking calcium about 1 1/2 years ago due to these reports. (about 1400 mg per day from Calcium citrate) along with vitamin D3 and magnesium ea day. I am just confused as to what to take. Am on Coumadin so don’t know about taking Vitamin k, — what to do??.
    My Dr. said to get more calcium from food which I am doing. How much is enough, how much is too much? I have been dx with osteopenia about 7 -8 years ago, recent dexa shows no worsening of the bone density. Also how about the calcium carbonate and tricalcium phoshate added to some of the non-dairy milk drinks?. What to do???
    People’s Pharmacy response: It sounds as though you are doing well by getting your calcium from food since your bone density is still the same.

  2. KATHLEEN V.
    Reply

    @ RV – thanks so much for the added information. I researched a little more after your comment and found that gallstones are formed by cholesterol. Very helpful to know. My sister has kidney stones, as well as the stones that were in her gallbladder. The doctor said the kidney stones were not causing her any problems at this time. He just removed her gallbladder.

  3. RV
    Reply

    Thanks, but gallstones are not the same thing as kidney stones. They are made up of an entirely different composition and involve totally different dietary implications not involving calcium.

  4. KATHLEEN V.
    Reply

    RV – I feel this is true as well. I have a sister that never drank any milk her whole life. She just had her gallbladder removed (65 yrs.) It was filled with stones.

  5. RV
    Reply

    I have to disagree somewhat with the statement regarding calcium and kidney stones. They did used to say to limit calcium because it contributed to calcium oxalate kidney stone formation. However, more recently some are now saying somewhat the opposite. In fact my doctor told me that taking a calcium supplement WITH meals could help prevent calcium oxalate stone formation. Calcium in the diet actually binds to oxalate and prevents it from ending up in the urinary tract and forming stones. (See http://kidney.niddk.nih.gov/kudiseases/pubs/kidneystonediet/index.aspx#calcium)

  6. jk
    Reply

    I too drink unsweetened Almond Milk, in my coffee, cereal and anything else that requires milk. I feel a whole lot better.

  7. wendy
    Reply

    “Save Our Bones” by Vivian Goldschmidt is an excellent online resource.

  8. vj
    Reply

    If you are lactose intolerant, coconut milk and almond milk are available and both are delicious. They are probably better for adults than cow’s milk anyway.

  9. KATHLEEN V.
    Reply

    @ MI — I no longer take calcium tablets. I switched to just taking Vit D3.

  10. MI
    Reply

    I would appreciate some guidance for those of us who are *allergic* to milk. I am a 52-year-old woman with an adult-onset allergy to milk. 21 years ago, my milk problems began with lactose intolerance. I was able to eat dairy products for the next 10-15 years, along with lactase tablets. When the tablets stopped working, I got off dairy products completely.
    Approximately 3 years ago, I was diagnosed with the alpha-gal allergy. Alpha-gal is found in mammalian cells, so I am now allergic to milk as well as red meat. I can tolerate only tiny amounts of milk (such as a small amount of cream in my coffee). For the past 6 years, at least, I have been taking a low daily dosage of calcium citrate (500mg) with magnesium, and 1400 i.u. vitamin D3. (I also have low vitamin D levels.) I know that my calcium dosage is below the recommended daily amount of calcium, but I am worried about the studies cited above, and also find it hard to take so many pills every day.

  11. GA
    Reply

    All of this could have been avoided if we listened to Harvard scientist Walt Willett in 2001. He showed convincingly how osteoporosis was extremely prevalent in countries with HIGH calcium intake and, paradoxically, low in countries with LOW calcium intake.
    Didn’t anybody see
    http://www.health.harvard.edu/fhg/updates/Do-we-really-need-all-that-calcium.shtml
    PEOPLE’S PHARMACY RESPONSE: You might be interested in our interview with Dr. Willett on this topic:
    http://www.peoplespharmacy.com/2010/09/04/752-bone-vitality/

  12. SAH
    Reply

    I recall discussion of this by David Wolff in his Longevity Series about a year ago. He mentioned calcium carbonate and associated inflammatory problems. I think this is important to follow up on and include in the discussion.

  13. PP
    Reply

    Thank you, GM. Yes, I keep Lactase or similar products on hand for when I get into social situations where not eating dairy is not an option or would “create a scene.” But all they do is stop the gas, and when I see the end product, I don’t think much nutrition is absorbed from whatever is eaten.
    Thank you though, for the suggestion.

  14. wendy
    Reply

    The Lactaid tablets sound like a great idea, but they don’t help me at all in regard to lactose intolerance. I’ve tried many times, with different brands of Lactase. Anybody else?

  15. GM
    Reply

    PP, if you are lactose intolerant, you can buy Lactaid tablets at any pharmacy without a prescription. (They provide the enzyme you lack to break down the milk sugar.) Also many big drug chains have their own brand of lactase enzyme, that may cost less and be just as effective. Good luck!

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