The Problem with Calcium Supplements

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The problem with calcium supplements
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Calcium is one of the most well-known but misunderstood minerals. It is added to everything from cereal to orange juice, yet there is a lot of evidence that supplements are not effective and may even be harmful…

Calcium Supplements: The Problem

There are several supplements that I personally take daily, even when eating a very high-quality real food diet because it is difficult to get enough of these nutrients from our modern food supply.

Other vitamins and minerals (like calcium and sometimes folic acid and iodine) are actually over-abundant in our current food supply and may be harmful.

Calcium is naturally found in dairy products and is often added to dairy and dairy-substitutes. Calcium is also added to many processed foods, cereals, breads and juices. Many people also take calcium supplements, especially during pregnancy and post-menopause, but recent research calls this practice into question.

Like so many other nutrients, Calcium needs cofactors (other vitamins and minerals) to be absorbed. Without these, calcium supplements are not bioavailable and may be harmful.

A 2012 study published in the British Medical Journal showed that those who took calcium supplements had a 139% higher risk of heart attack, though this increased risk was not present when the same amount of calcium was consumed from whole food sources. (1)

Other studies have shown the same correlation:

  • A 2010 meta-analysis showed that calcium supplementation increased the risk of stroke, heart attack and death from all causes (2)
  • A study published in JAMA in 2013 showed that supplementation in excess of 1,000mg/day was associated with a 20% increase in risk of death from cardiovascular disease. (3)
  • Other studies, like a recent one published in the American Journal of Clinical Nutrition showed that calcium supplementation increased risk of kidney stones and prostate cancer (4)
  • Chris Kresser showed that this risk is even higher in women “Additionally, a recent Swedish study reported a 40% higher risk of death among women with high calcium intakes (1400 mg and above), and a 157% higher risk of death if those women were taking a 500 mg supplement daily, compared to women with moderate daily calcium intakes (600-1000 mg).” (5)

So why does it appear that calcium supplementation can increase the risk of heart related problems?

Two possible reasons…

  1. Researchers speculate that when supplemental calcium is taken, it cannot all be absorbed and the excess is left circulating in the blood, which can lead to calcification in the arteries, or is excreted in urine, which may lead to kidney stones. (Here are natural remedies for kidney stones.)
  2. It is very difficult for the body to absorb many forms of calcium, especially when they are taken alone, as it needs cofactors like Vitamin K2, Magnesium and Vitamin D to be properly utilized.

Calcium for Bone Health?

But, what about bone health? Turns out, calcium supplements aren’t the silver bullet for bone health either…

A 2012 study showed that supplemental calcium (above the recommended amount from food) did not increase bone density or reduce fracture rate. (6)

In fact, in 2013, the United States Preventative Services Task Force reviewed 135 studies on calcium and rate of fractures and recommended that post-menopausal women STOP taking supplemental calcium. (7)

Food sources of calcium (like dairy, bone-in meats and certain types of fish) were shown to be beneficial for bone health without the increased risk of cardiovascular and other problems.

Dairy is the most recommended dietary source, but there are some confounding factors. Numerous studies in several countries have shown that dairy consumption reduced the risk of osteoporosis, hypertension and other problems associated with these diseases. (8,9,10)

Some in the natural health community claim that dairy is actually bad for bones because dairy products acidify the body, causing it to pull calcium from the bones to re-alkalize.

Chris Kresser thoroughly explained (and debunked) this theory, and a 2011 study reviewed this theory and found no scientific evidence to substantiate it. (11)

A Better Option: Food Sources of Calcium

The available literature points to the same conclusion that many of us feel intuitively- that food sources are better than supplements whenever possible and this is especially true with calcium.

Dairy is a controversial topic, since many people do not tolerate it or choose not to consume it. Fortunately, while it is the most well-known dietary source of calcium, it is by no means the only source and others may be better. Also, research suggests that the most beneficial part of dairy (especially raw dairy) for bone health may be Vitamin K2, not calcium. More on that below…

Wonderful non-dairy sources of calcium include:

The Importance of Cofactors

Cofactors are also vital for proper calcium absorption and use in the body. In isolation, calcium (and many nutrients) can be harmful, as I explained above, but it is vital and helpful when consumed in proper balance with its cofactors.

There is an excellent book called Vitamin K2 and the Calcium Paradox, which explains in depth how Vitamin K2 is needed for proper utilization of calcium and how calcium consumption without K2 can lead to health problems.

K2 is found in raw dairy from pastured cows, liver, aged cheeses and natto (a fermented soy product). It is also available in supplement form.

Other cofactors for calcium include Vitamin D and Magnesium (among others). In fact, K2, Calcium, Magnesium and D3 are all better utilized when consumed together.

Personally, I prefer to get my Vitamin D from the sun whenever possible and my calcium from food, but I take supplemental forms of Vitamin K2 and use transdermal magnesium to keep my levels in optimal ranges. (This is a great quiz to see if you are deficient in magnesium).

Bottom Line…

Supplemental calcium is not the panacea for strong bones that it is made out to be. Calcium is certainly important, but it is most beneficial when it comes from food sources and when taken in proper ratio with its cofactors.

Do you take calcium supplements?

Katie Wells Avatar

About Katie Wells

Katie Wells, CTNC, MCHC, Founder of Wellness Mama and Co-founder of Wellnesse, has a background in research, journalism, and nutrition. As a mom of six, she turned to research and took health into her own hands to find answers to her health problems. is the culmination of her thousands of hours of research and all posts are medically reviewed and verified by the Wellness Mama research team. Katie is also the author of the bestselling books The Wellness Mama Cookbook and The Wellness Mama 5-Step Lifestyle Detox.


53 responses to “The Problem with Calcium Supplements”

  1. Hannah Avatar

    Great post! My family and I all grew up taking calcium supplements (I am now in my late 20’s). My mother (entering her 60’s) has been working with a homeopath and has learned she was getting waaaay too much calcium. After reading this, I definitely think co-factors were a missing piece of our nutrition equation!

  2. Wanda Avatar

    Nothing here about the other members of the bone team? Hmmm? Magnesium? Vitamin D? K2 anyone? Taking only one nutrient puts you out of balance.

  3. Linda Avatar

    Thank you, you have just stopped me buying a calcium supplement. I would have been panic buying after being told it is likely I have osteopenia
    Do u consider Organic Acai powder a reliable calcium source (id like to add it to my homemade smoothie)

  4. Leslie Lefevre Hanson Avatar
    Leslie Lefevre Hanson

    I tried many for years from the health food store and then read about one in a book about diet while pregnant. I finally tracked this one down and have used it for 40 years. No cavities if I stay on it, no chiropractor visits for the last 40 years after going 2-3 times a week in my 20s!! She said she could not help me with my back problems and sciatica until I stopped carrying babies! I had one then! Now I have 7 grown up children and 20 living grandkids!, can dance for hours at 66, rarely have joint pain and can heal up fast, play volleyball, don’t break anything when I fall, pick up my heavy grandkids wrong, had births that were up to 50X easier from number 3 on, do 200 squats a day and got rid of insomnia!

    Yes it has Vit. D (not much sun here!), Magnesium and double amino acid chelation. My back problems were gone in about 10 days! I have not found another company that goes to these lengths. There are also many stories of healed bones including backs. One is our 39 year old daughter with x-ray proof that she rehydrated a disc from a tailbone injury as a kid. (she included a couple of other items as well) So, know your company, don’t try to cut costs or corners. Calcium deficiency is one of the top ones in our country. I used to despair of having all the digestion and absorption needs in place but I found answers!

    I have to add that we use A2 raw milk and other dairy, make green, green (I call them industrial strength) smoothies, eat way more veggies than most, avoid sugar like the plague along with other refined foods and still get much benefit from this Calcium supplement. I am sorry there are so many bad ones out there.

    1. Nicole Avatar

      Leslie, I know your comment is so old but I thought I would try my luck! Would you mind sharing the supplement you were able to find?

  5. Kasia Kiliszek Avatar
    Kasia Kiliszek

    Hi there
    Very interesting article. I have a question, if I may.
    I’m allergic to milk products, (lactose free product doesn’t work for me) soya and peanuts. On top of that, I’ve been vegetarian for 15 years and I don’t eat sugar. Do you think taking calcium as a supplement is a good idea? My diet includes lots of kale, spinach and beans but of course, not everyday. I believe in moderation when it comes to diet. Any thoughts?

    1. Katie - Wellness Mama Avatar

      Good question. I’d find a naturopath or nutritional therapist who is well versed in navigating this for someone on a vegetarian diet. I get most of my calcium from sardines these days and don’t have any first hand experience with a vegetarian diet to be able to share here.

  6. Saby Avatar


    I enjoyed reading your article with supportive research. I also learned a few things. The idea of adding Magnesium and Vitamin K2 is beneficial to me because I suffer from Hypocalcemia and Hypoparathyroidism. The supplementation of calcium carbonate and calcitriol seems to be hurting me a whole lot. I’ve had pain in my heart often and bouts of arrhythmia when calcium is very low. I have no choice, but to take these meds. It’s disconcerting. Anywho, I have taken these meds and everytime I do it seems to irritate the abnormal uterine bleeding. I bleed for days and days. It’s neverending. I am really frustrated with my condition and the medical doctors especially when they tell me there is nothing they can to for me.

    In a recent Endo conversation, the doctor wanted to force me to accept that NatPara injections. I refused. There is a chance that with high dosages and a prolonged use of the drug that I may develop osteosarcoma. I research every drug and medical condition. I don’t take meds without knowing the side effects. My dilemma is why doctors tell me these meds won’t hurt and have me double dosing knowing that it increases my risk of cardio disease. I have had a healthy heart and have been watching my pressure rise up to 174! I am very concerned and much rather not take the supplements only the vitamin D2, magnesium, and vitamin K2 and calcium from blackstrap molasses.

    Do you have any information on these conditions?

    Thank you.

    1. Connie Avatar

      Sorry my reply is so long in coming. I had a rough October. I’m not that familiar with Hypocalcemia or Hypoparathyroidism. I’ve been retired since 2009 and never considered how easy it is to forget things. I’m like you and don’t want to take meds without knowing something about them. I trust my doctors to order a safe dose and the right medication for me. I trust the Lord more to keep me safe!
      I wish there was an easy answer. I need one too. We should be able to get what we need from our food, but that doesn’t seem to happen. My last lab work had my Mg 0.2 above normal. I was taking a few extra because of changes in my medications. The thing about that was everything I read said that a serum level will not give an accurate Mg level. How could every single article say it would not, when it actually can? Maybe the labs have changed their way of testing? I’m at a loss myself.
      The supplements you’re taking sound good, but you have to remember some things take time. It would be wonderful if they made a health pill that we could take before bed and wake up well! I’ll keep you in my prayers.

  7. Nur Fadzlin Ahmad Avatar
    Nur Fadzlin Ahmad

    Im 20 weeks pregnant. Im finding it hard to swallow pills and i just bought these rainbow light calcium citrate chewables. But i just realised they have herbs in them like stinging nettle, raspbery tea leaf and alfalfa in them. Would really appreciate if i could have your opinions on them and whether i should not consume themThank you

    1. Connie Terpack Avatar
      Connie Terpack

      I’m sorry but I’m not comfortable answering this. I am not a professional nutritionist and do not know how herbs affect a developing fetus. You should talk with your doctor who can refer you to someone who can help. Sorry. Connie

  8. Jamie Avatar

    Organic eggshells. Research it. Works great. It’s absorbable and the same structure as our bones and teeth. Several ways to consume… I personally grind mine in a coffe grinder after boiling them. You could use the water but I give that to my vegetable garden. Dry the shells in the oven on the lowest temp for 10 minutes grind in coffee grinder and add to smoothies or put in veggie capsules. 1/2 teaspoon-1 teaspoon should be plenty. k2 I get from organic eggs and organic ghee butter, I also take magnesium via transdermal homemade magnesium oil and fermented cod liver oil which is high in vitamin D and 15 minutes of sun every 2 hours. Minimal clothing or naked is even better if you have a private yard ;). I think the supplement pills are not regulated and you don’t know what kind of fillers or the source of calcium so make your own. Use in moderation if your poop gets hard you’re taking too much.
    I’ve remineralized and healed teeth that should have been pulled using this method. So I think it’s working. Cheers to everyone trying to maintain health in this world that has been damaged and depleted of so many beneficial nutrients. All the Best!!

  9. Lola Avatar

    We were advised to take a calcium + magnesium supplement as we are in a low amine and low salicylate diet to try and get over my daughters eczema she is 13 months old and I’m still breastfeeding a couple of times a day.

    Does anyone know whether these supplements are correct when doing this kind of diet which makes you avoid A lot of foods?

  10. Laura Avatar

    My mom was told to take very high daily amounts of calcium supplement daily because the med she was put on after completing radiation for breast cancer depletes bones. Anyone have any experience with this? I’m going to share this info with her.

    1. Mandy Avatar

      My mother was told the same thing, and I’m concerned about this. She won’t listen to me, only her doctors… I have heard that carbonate can, in addition to everything described above (and was mentioned) can also cause “brain gravel”, which has been found in patients with Alztheimer’s. My Nana (her mother) died from that and breast cancer, caught extremely late, in her early 80s, and she passed a decade ago next month at 84. My Mom was lucky, she detected it early, had surgery, and chemo + radiation, and it seems to have all been removed. But this frightens me.

  11. Connie T. Avatar
    Connie T.

    I’m glad to hear the magnesium (Mg) is helping with the muscle cramps and vertigo. The list I have of problems related to a low magnesium is lengthy, but I don’t think it was all inclusive. Magnesium is classed as an essential mineral and is used by every body system. It may not be known all the symptoms of low Mg. I’ve been surprised by the difference in symptoms from person to person.
    You didn’t mention how much Mg you’re taking. Have you noticed any other problems that the Mg has helped? Also, my apologies for my delayed response. I had planned to do another blog on Mg. I’ll add your comment to the discussion.

  12. Frank Avatar

    I’m very pleased to have come upon this site. In another post you site the use of magnesium supplements which I have been taking since experiencing muscle cramps. Much later after convalescing from a knee replacement I began to experience severe vertigo while lying down and standing up. A therapist said that vertigo is due to the build up of calcium carbonate crystals on the cilia of the inner ear (responsible for balance). I noticed (correct me if I’m wrong) that there was no mention of vertigo as a problem for lack of magnesium in that other post. As it were, I have been taking Mg supplements along with plenty of water to help dissolve the crystals. Muscle cramps and vertigo are no longer a problem.

  13. Erin Avatar

    A few months after I started taking calcium supplements, I got kidney stones! So painful. Don’t want to do that ever again!!!

    1. Connie T. Avatar
      Connie T.

      Sorry to hear that. There are different types of calcium, but I don’t remember which kind is more prone to forming kidney stones. My doctor put me on calcium about 5 years ago and I’ve had no problems with it.

  14. Craig Hitchens Avatar
    Craig Hitchens

    Interesting article. As a Naturopath I see first hand the effects of poor nutrition and over supplementation. Whilst I am in agreement with the main basis of your article, calcium supplementation remains a useful tool for those who need it and people need not fear it. Bottom line is compliance; not everyone is going to eat healthfully enough to guarantee the levels of calcium and co-factors needed for therapeutic effect. So the need for supplementation arises and remains.

    This is where you need to obtain professionally formulated supplements that do have all needed co-factors for proper absorption and the way to do this is through visiting your Naturopath or Doctor for testing to ascertain what minerals etc need to be supplemented and by how much and for how long. This is the real point here; professionally formulated supplements used under supervision after testing, not using poorly made retail lines with no idea what you are doing.

    I see many people on a daily basis who over use supplements of all kinds and they do contribute to imbalances. Whilst the research is good it fails to take into account whether or not people were supplementing under supervision or what quality of supplements they were using so we are left to assume that.

    What I can tell you is that a properly designed supplementation program administered under supervision is the best option if you are thinking along those lines and I highly recommend seeing your Naturopath or Doctor before you embark on such a regime. 🙂

  15. Nessa Avatar

    Thank for the article Katie. I think everyone would agree that whole-food options are always the best choice for all vitamins and minerals, but of course that isn’t always possible, so it is important to think about what you are putting in your body and why.

    One note: I appreciate that in your article you specifically mention raw dairy. Not all dairy is created equal and the nutritional differences between the grocery store pasteurized, homogenized dairy and fresh, raw dairy are plentiful. Raw dairy is a living food that has a plethora of pre- and pro-biotics, vitamins, and minerals. If you think you are lactose intolerant or “can’t tolerate” regular, grocery store milk, I truly recommend seeking out a raw milk source close to you and trying it. Your body will thank you!

  16. Juliet Avatar

    What about calcium supplement use during a fever? white blood cells needs calcium to be produced. During a fever, WBC production is up, therefore so is calcium demand, which is taken from the bones, which in turn causes the ache. First, is this true, and if it is, is a supplement helpful? I would think that it would provide the extra calcium necessary so it wouldn’t have to be taken from the bones. What kind of supplement would be best, if it should be taken at all? Or would some good bone broth do the trick?

  17. Lauri callen Avatar
    Lauri callen

    I am in the sun a lot EVERY day; yet with my last blood panel evaluation I still showed low vit D. My doctor says most individuals are low in this area and supplementation is always beneficial. Since I’ve been taking D3 sups, my nails and hair have noticeably improved!!!

    Thanks for all your invaluable information!!

  18. Jann Avatar

    Very interesting post. I’ve recently starting putting a small amount 1/4 teaspoon of ground eggshells (organic and no soy in the feed) into my daily routine. I’ve heard that the calcium from eggshells is better assimilated in the body than the calcium from supplements. I wonder if this source of calcium from shells would be less likely to produce some of the negative outcomes as mentioned in your post. Not sure if I should continue with eggshells now.

  19. CAPERNIUS Avatar

    I take calcium supplements every day…2 & 3 times a day actually…
    all the blood tests I’ve had, & all the CT Scans I have had, have not shown anything wrong or out of place…
    I’m a cancer survivor (15 yrs), so I have frequent flyer miles when it comes to scans & blood work.

    I have always been a healthy eater & always in the best of health (till I got cancer from where I worked)….I started taking supplements when I was in the military @ 19 yrs old…I retired in 1999 & in february of 2000 I was diagnosed with head/neck cancer….I can no longer eat regular food like everyone else does….so I depend on supplements to fill in the nutritional gaps.
    I’m like the toy weebles from yrs past…”…weebles wobble, but they don’t fall down…”
    Life keeps knocking me down, & like the weebles, I keep bouncing back up. : )

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