Diabetes Medication

Stop Taking Calcium Pills

Stop taking calcium even if you have diabetes: It doesn’t work and it has side effects, including heart attacks. This is the blunt message of recent studies of this mineral.

Our doctors have been telling us for years that we need 1,000 to 1,200 mg of calcium to prevent osteoporosis and bone fractures. They were wrong, they now admit.

calcium foods

Because of this bad advice more than 60 percent of American women aged 60 or more were taking calcium supplements a few years ago, the U.S. Centers for Disease Control and Prevention said. Nevertheless, some researchers wanted us to take even more calcium: “Americans are not meeting current calcium recommendations,” according to a 2007 article in The American Journal of Clinical Nutrition.

Our doctors particularly encouraged people with pre-diabetes or diabetes to get more calcium. For example, taking a calcium supplement might reduce the risk of type 2 diabetes, according to a study that Diabetes Care reported in 2006.

The change of heart has been a long time coming. As early as 1991 the  cardiologist Dr. Stephen Seely wrote in the International Journal of Cardiology that excess calcium was a major cause of the buildup of plaque in our arteries.

“Omit All Calcium Supplements”

I didn’t know about Dr. Seely’s report until recently, but in 2007 Dr. Joe Prendergast, an endocrinologist practicing in the Bay Area of California, warned me in his email newsletter to “omit all calcium supplements,” and I did. Dr. Joe has always been on the leading edge of medicine, and I admire him so much that I picked him to write the foreword to my second book, Losing Weight with Your Diabetes Medication.”

Still, from the point of view of the American medical establishment the first nail in the coffin of calcium supplements didn’t appear until five years ago. That’s when the leading British medical journal BMJ in 2010 and 2011 published two meta-analyses concluded that calcium supplements increase the risk of both heart attacks and strokes.

The Calcium Coffin Is Shut

But not until about a month ago did researchers finally nail the calcium coffin shut. Again it was BMJ that published the damning studies, and again the studies came from a team of researchers in New Zealand. The full-text of the studies are free online at Calcium intake and bone mineral density: systematic review and meta-analysis and Calcium intake and bone mineral density: systematic review and meta-analysis.

“Dietary calcium intake is not associated with risk of fracture, and there is no clinical trial evidence that increasing calcium intake from dietary sources prevents fractures,” they wrote. “Evidence that calcium supplements prevent fractures is weak and inconsistent.”

“Adverse Effects”

Worse, “Clinical trials of calcium supplements at doses of 1,000 mg/day, however, have reported adverse effects, including cardiovascular events, kidney stones, and hospital admissions for acute gastrointestinal symptoms,” the team wrote.

Already the news has reached some of our doctors. A week or two ago my primary care physician at the local Kaiser Permanente clinic told me not to take a calcium supplement, and I replied that I didn’t. If your doctor hasn’t got the word yet, you can say that you heard it here first.

This article is based on an earlier version of my article published by HealthCentral.

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  • John Smith at

    What converts K1 into K2 is microbes, and ONLY certain microbes.

    If you’ve ever seen the studies of how people who were breast fed as children have better teeth & bones, well that kind of points to why. It wasn’t the milk, or the vitamins in the milk, it was probably the mothers natural biological flora (germs) that got into that infant early, and took hold. Years later, that same intestinal flora is able to take K1 and turn a significant amount of it into K2 Mk4.

    Case in point: My older brothers, all of whom were breast fed, have had almost no dental problems throughout their lives. Me (and my sister) on the other hand (not breast fed), have much more dental problems. Same diet growing up, (except for breast feeding), same genetic background, yet very different outcomes.

    Bottom line: I think how much K1 gets turned into K2 varies depending on your individual gut flora, with other possible genetic variables. So getting adequate K2 via K1 ingestion is probably somewhat dubious for many/most people.

    I don’t see ANY need for a K1 supplement in most normal people. Eat a salad or even some green veg once in a while, you’ll get plenty of K1. K1 also recycles itself in the body, K2 can’t do that. K1 sources are plentiful and cheap, where as K2 sources are not either of those.

    Although K2 is important, don’t overlook magnesium & D3. Most people are deficient in both magnesium & D3, and in a lot of ways they are key for proper bone construction and many other body functions.

    What I’m saying is that these vitamins don’t work in isolation, they work together in a synergistic manner. So if you take the expensive K2 pill, but skip the relatively cheap D3 and/or magnesium (citrate), the K2 will do nothing for you then… Oh, and you have to take all 3 of those with some fat in order for them to be properly digested.

  • Neal at

    Agreed in a proper metabolic context good thyroid function and vits a-d-k calcium is not an issue. Not necessarily calcium at fault, but unhealthy body and inability to manage calcium appropriately.

    Regarding Vit K: K1, MK7 and MK4 have different activity in body as well as different half-lives. I’ve read in journals that the body can convert certain K’s in to other K’s but this pre-supposes healthy body an ideal conditions.

    I take Super K from LEF which has K1, MK4, and MK7.

  • Wen at

    Hi David,
    The vitamin k question? Which should be taken as a supplement along with vitamins D and A: MK 4 or MK 7? Reasons?
    Thanks a bunch!

    • David Mendosa at

      Well, Wen, the one I am persuaded to take is the MK 7 form of vitamin K2.

  • John Smith at

    Hi David,

    *WARNING: K2-MK4 should NEVER be taken if you are on warfarin / coumadin !!!!! (same applies to magnesium citrate to a lesser extent).

    Well, there are two reasons she favors K2-mk7. First of all is the reason you mentioned (longer half-life), but mostly because the Canadian government (like most doctors) treats all forms of vitamin K (1 or 2) equally, and only allows a maximum of 90 or 100 mcg per dose to be sold in stores. I.E., you can’t get K2-MK4 in any useful dosage there. Its minimum “useful” dosage is 45mg (15mg * 3). The reason they do this is because they don’t want scores of people (who are too lazy or stupid to read the contraindicated medical literature on the pill bottle) dying off because they decided to try out a non-prescription supplement they found on the store shelf (hence the warning up top).

    The longer half-life thing is a bit counter intuitive though. Most people automatically think that it means it will do more good the longer it is in you. What it probably means, is that it is not as bio-available as the K2-MK4 form. In fact, at higher doses K2-MK7 can start having adverse affects on some people (i.e., starts getting toxic). There are NO known upper dosage limits for K2-MK4 according to the studies I’ve read.

    If you actually look at the research that has been done, it is K2-MK4 (not MK-7) that has been scientifically shown to reverse osteoporosis (in double blind studies) fairly rapidly (reduced fractures by 81% within a years time). GLAKAY is the “medication” the Japanese used (since 1995) to do that with, which is basically 15mg of K2-MK4 mixed with MCT oil. The recommended minimum dosage is 15mg * 3 times a day, taken with meals *must eat a minimum amount of fat to digest it properly.

    I think it’s been mostly “food studies” and “meta studies” that have shown the effects of higher K2-MK7 dietary intake (natto, cheese, etc). This is not to say that the MK-7 form isn’t useful, it just takes longer, and works better as a preventative/maintenance measure over ones lifetime.

    Here is what I think happens. Again, MK-7 is not very bio-available in the body, however I think the liver probably turns it into the more useful MK-4 form over time. This is basically what happens when cows eat grass. The K2 in meadow grass is MK-7 only, which actually comes from the bacteria in the ground BTW (just like natto). This is why pastured animals have high levels of K2-MK4 in their meat, milk, eggs, etc…. Also, their livers are more attuned to turn MK7 into MK4 than ours are. Most people on a SAD are not eating pastured animals, or their tertiary products, and therefore get little or no K2 in their diets. Hence the much higher rates of osteoporosis and arteriosclerosis since the late 1940’s when industrial farming really took hold.

    So, the MK7 form is kind of like being on a constant low level IV drip, and should prevent most bone/artery calcium problems when taken early and throughout life. Whereas the K2-MK4 form can be used as more of high dose “medicine” to rapidly reverse problems, caused by our poor dietary food supply, at a much faster rate than is possible with Mk7.

    The really sad historical fact is that this version of vitamin (K2) was totally ignored by the person who discovered vitamin K (gimme my Nobel, cya l8r). Weston A Price (google him) nearly discovered this secret vitamin, but only knew it as “activator X”. Although passionate and determined, he didn’t have the scientific background or resources to isolate it (he was a dentist). However, he did know what foods it was in, mainly pastured livestock and related food products (pastured butter & milk), and he also knew you needed cod liver oil (vitamins D3 & A) for it to work properly.

    Interestingly, studies also show people that get adequate amounts of K2 have higher testosterone levels, yet have much lower incidences of prostate, testicular, and breast cancer (unlike the “Low T” big pharma junk they’re getting sued over now). Think about it, where do your blood cells come from? From inside YOUR BONES. Yes, your bones are not just a basic support structure, they are also a key part of your endocrine and immune system. K2 (along with D3, magnesium, & A) quite literally feeds your bones.

    Sorry 0

  • Marie at

    Wow! Glad I read this! Just literally got out my calcium to start taking it with my Vit D.

    Not any more!

  • Bruno Karlin at

    Yes indeed, so frustrating.
    Everything we eat is interconnected.
    Yet medical research is so reductionist.
    Too often Big Pharma behaves like the medieval church.
    Thank heavens for metastudies and brave publishers.

  • Randye Wolf at

    Because I have (had) osteoporosis, I have been taking calcium and vitamin D3 (3000 mg) for years. About 4 years ago I added Mk -7 (I believe about 200 mcg. but I’m not home to check) plus a small amount of Mk-4. I use the Super K from Life Extension. I also have been taking about 500-1000 mgs. of Magnesium for many years – citrate or taurate or the other forms except not carbonate.
    I am a pre-diabetic for about 10 years; I just take Metformin (generic, unfortunately) and manage to keep my A1c at 6.0 through diet and the Metformin.
    I have begun to take 650 mgs. of Strontium several months ago; the osteoporosis became osteopenia but I am not sure if that effect is real or an artifact caused by the way strontium affects the Dexa test.
    Any suggestions?

    • David Mendosa at

      I don’t know anything about strontium, Randye. But everything else sounds good and probably well in balance.

  • francine harris at

    Dear Dr. Mendosa: Please advise on taking ‘ Caltrate Calcium and Vitamin D3 Supplement, they are Gummy Bites, good tasting. I have diabetes for years and my hubby has A-Fib.. thanking you in advance for your response…

    • David Mendosa at

      I don’t think from reading the reports that we have the evidence yet to warrant taking calcium supplements even with vitamin D, unless perhaps — and we don’t have much evidence here — that we also supplement it with the right levels (which I don’t know how to determine) of magnesium and of a certain form of vitamin K2 as well.

  • francine harris at

    Dear. Dr. Mendosa… How about the chewables – Caltrate – calcium and vitamin D3 supplement.
    they are gummy bites….. please advise. I am a diabetic for about 10 or more years., my hubby has A-Fib, and I also give them to him..thank u in advance for your reply.. Francine & Philip Harris

  • Roxanne at

    Have recently learned of this calcium dilemma and dropped my supplements. (Surgery scheduled in 2 weeks on “staghorn calculus.”) have also stopped taking the multi-vitamin, which includes calcium. I feel like it is more than a full time job keeping track of diabetes 2, nutrition and current research. But…thank you for this site and all the research you make available to us. Happy, healthly, new year, All!

  • diana at

    Calcium in any form always gave me loose stools, very loose. When I lived in Italy for a few years, a gyn doc told me that we really don’t absorb the calcium taken that way, and I can believe it. Eat green leafy veggies are the best way to get calcium

  • L. Paul Teague at

    Ron Rosedale, M.D. told my wife and me not to take calcium supplements in 1998 when he advised my wife on the control of her newly diagnosed Type 2 Diabetes. As a result, she has maintained normal A1c and fasting blood glucose readings since then. Thanks to Dr. Rosedale she stopped adhering to the American Diabetes Association guidelines which were causing her blood glucose readings and A1c to greatly increase. The ADA guidelines were — in effect — malpractice [in my opinion]. They made things worst — not better.

    • David Mendosa at

      Your wife is so lucky to have had Dr. Rosedale as her doctor, Paul. He is much wiser than the ADA has ever been.

  • Kristi J at

    I think I still need to take this because I take a medication for five years after breast cancer which has the side effect of depleting calcium.But after I am finished with that, I believe I will stop.

  • SueT at

    And how much K2 to take? I’ve seen capsules up to 100 mg

    • David Mendosa at

      This is a more complex question that I can address here, Sue. In fact, it needs a book to answer it. Fortunately there is one. It is “Vitamin K2 and the Calcium Paradox” by Kate Rheaume-Bleue.

  • Michelle at

    Nora Gedgaudas, Certified Nutrionalist/Educator, has been saying this for years.

  • John Smith at

    RE: Michele Lee’s comment….

    The reason people with higher protein intake are probably faring better, may be because they were getting more vitamin K2-MK4 (which is highest in grass fed/pastured livestock).

    The Japanese have been using large pharmaceutical doses (15mg x 3 times daily) taken with meals (it’s a fat soluble vitamin) for some years now. It doesn’t just slow down or even stop osteoporosis, but REVERSES IT completely. I think it’s call GLAKAY or something like that. Keep in mind most Japanese do NOT drink milk or eat cheese, as most all Asians are lactose intolerant. The landmark study they did (over a decade ago) had 81% less fractures in one years time.

    You can make your own Glakay, just get some K2-MK4 vitamins (Amazon) in 15mg doses and take a teaspoon of coconut oil with it (medium chain triglycerides makes it absorb better).

    There have also been some meta food studies on populations who have diets rich in either k2-MK4 or k2-mk7 (natto) which shows they have a lower rate of heart problems and osteoporosis versus a similar population that eats foods with less/no K2. I.E., People on the east coast of Japan eat natto, west coasters don’t….

    This also explains why some studies on D3 say it’s good for your heart, and some say just the opposite. The missing component is K2. If it is not present in the diet, the D3 causes too much calcium to be absorbed into the blood with nowhere for it to go. With K2, (and enough available D3, magnesium, phosphorus and A) the calcium is taken out of the blood and put where it belongs into the bones.

    I’ve been taking 15mg x 2 for the last six months to clean out my arteries (family history of heart problems), and it seems to be working (no more angina).

    A good book on this is called “Vitamin K2 and the Calcium Paradox” by Kate Rheaume-Bleue. She advocates for k2-MK7, mostly I think because they are not allowed any type of vitamin K in Canada over 100mcg dose. Most osteoporosis and heart studies that have shown dramatic results are on the MK4 type.

    My theory is that k2-mk7 can be metabolized by the liver and turned into k2-mk4, but cannot be used directly by the body. So I think the mk7 type helps to slow down problems, but I don’t think it can reverse them very quickly. But, I take both anyways….

    In case you are wondering, the SAD diet has little or no K2 in it since the early 1950’s. Has to do with industrial farming (k2 only comes from meadow grass, not grains).

    • David Mendosa at

      Very interesting, John. I really appreciate your comments. I take vitamin K2 and eat natto sometimes. I will start following up your comments and just requested the book you recommend from the local library.

    • David Mendosa at

      Thank you, John. I appreciate so much that you referred us to the book “Vitamin K2 and the Calcium Paradox” by Kate Rheaume-Bleue. I just obtained it and read it carefully. As a result I learned a whole lot. This is an outstanding book! As a result I ordered a different vitamin K2 supplement, one of the K2-MK7 form. My reading of the book differs from yours, in this respect, however. She recommends it because of the very short half-life of the MK4 form. If you get a chance to re-read that section, please get back to us here.

  • Michele Lee at

    What indeed are we to believe? I just recently read this blog post by a longtime osteoporosis researcher at Creighton University who pointed out that with supplementation of calcium, vitamin D, and higher levels of protein, bone density can actually be regrown. This was founded on results in a trial at Tufts University.

    “…an insightful investigator at the Tufts Nutrition Research Center on Aging in Boston noticed that a high calcium intake did, in fact, lead to increased bone gain if the patient’s intake of protein was high. Bess Dawson-Hughes had previously published the results of a calcium and vitamin D supplementation trial, producing a better than 50 percent reduction in fracture risk in healthy elderly Bostonians with those two nutrients alone. But, like others before her, she noted that, while high calcium intakes reduced or stopped bone loss in her treated subjects, the two nutrients didn’t lead to bone gain. They didn’t, that is, in individuals consuming usual protein intakes. However, in a subset of her treated patients, who, it turns out, had protein intakes above 1.5 times the RDA (0.8 g/kg body weight), bone gain was dramatic (while it was zero in those with more usual – and usually thought “adequate” – protein intakes)… Only with the highest protein intakes was there appreciable bone gain.”

    I’d value your opinion on this.

    The Paradox of Osteoporosis Irreversibility


    • David Mendosa at

      Thank you, Michele, for finding this wise post and bringing it to our attention. Dr. Heanley makes a lot of sense to me, but so do the studies that show it’s not wise to take a calcium supplement. What he has is a hypothesis, which he himself says needs to be tested, “one that can be tested (and thus proved or disproved).” He is adding two more factors to the equation, namely protein and physical work, namely with “special emphasis in this instance on impact exercise, such a jumping rope.” If you are willing and able to do impact exercise as well as double the recommended protein input (and don’t have kidney disease, where that’s a bad idea), you might want to take a calcium supplement. The impact exercise for me at age 80 might also be a bad idea, but in the absence of a study, you might try it.

  • Helen O'Neill at

    I read this somewhere sometime ago and haven’t taken them regularly for a while. But in a way – this just blows my mind. What the hell can we believe?
    The whole lowfat thing was wrong and no one would admit it. The statin drug still prevails – even tho I refuse to take them. It is just so frustrating.
    Sorry – had to vent.

    • David Mendosa at

      All we can believe, Helen, is our own experience. Nutrition is half science and half opinion. It’s impossible to tell which!