The Problem with Calcium Supplements

The problem with calcium supplements

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.
  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:

  • Sardines (canned)
  • Salmon, with bones (canned)
  • Beans
  • Okra
  • Leafy Greens
  • Blackstrap Molasses

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?

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Reader Comments

  1. What do you give a toddler in substitution for dairy milk? Doctors always recommend homo milk starting at 12 months, and my little guy is now 20 months and I have been so conflicted about giving him so much dairy. I personally don’t consume it. I have been giving him almond milk lately (without carrageenan), and am hoping that this is an appropriate substitute for homo milk.

    • I had the same feelings with dairy and my kids. I give them organic hemp milk it’s so easy to make just hemp hearts and water. You don’t need to strain or soak them either. My kids love hemp milk over all other seed or nut milks. I also give them lots of fruit and veggies, raw organic cheese from a local dairy, eggs, and bone broth. I’m pretty sure they get enough nutrition and processed dairy milk has been processed in a way that really there is no nutrition left. The enzymes are dead and gone and it’s super sugary which isn’t good either. Follow your gut literally lol. Sounds like you’re on the right path!

  2. Yes 🙁 Yes I take Calcium. I was told to since I breastfeed and since I’m lactose intolerant. This is my 3rd child and I’ve taken supplements while nursing child #2 and #3. I take Calcium 600 mg with vit D 400 IU…ugh…now I feel I need to stop. Which is better to know now than later. Unfortunately, I just started my 10 year old on a suppliment a couple months ago…Calcium & Magnesium with vit D and Zinc since I did a lot of reading on OCD (which he was labeled with 3 years ago) and I kept reading how ppl with this anxiety disorder are low in these areas. Here it is…I’m trying…making own lotion, body wash, laundry, detergent, clearing out the plastic…weekly (daily) baby steps to a healthier, safer life style…it feels great! On the other hand…reading this post was insightful and VERY important…just tugs at my heart a bit…I took my calcium because of my doc…I gave my son his because of my reading and want to do everything in my power to help him conquer his anxiety disorder. Kinda feel like a mouse on a treadmill right now after reading this. 2 steps forward, 1 step back. Okay…I guess here’s to throwing out the supplements. I will say I understand receiving the nutrients from food itself is best…Thanks for the post…

    • You might also want to look into magnesium (Mg). I was an RN for 40 years and learned more about Mg after I retired. As a Home Health nurse I taught my diabetics to take Mg to control their sugar; my wound patients to use it to help heal. That was about all I knew about it. I was put on Mg for seizure control. My seizures were not frequent, but every epilepsy med caused such side effects that I finally refused to take any more. My neurologist already had be on B complex and suggested adding magnesium.
      The Mg benefits surprised me. I started studying up on it. It is needed for every one of our body functions. The 2nd thing that I learned was that a serum blood level will not give you a true Mg level. Mg is constantly circulating, so even at low amounts, it looks adequate. A cellular count needs to be done. If your potassium is low, chances are good your Mg is also. It is recommended for kids with ADD, ADHD, OCD and so on.
      Water used to be our best source of Mg. The fluoride added (not the natural fluoride normally found in food or water) binds with the Mg making it useless. The same thing happens with plants. Mg is decreased by all the additives and preservatives. I’ve been on Mg along with my other routine supplements for 10 months. I am sleeping better, don’t feel as skittish, and the fibro pain is gone. Still have the ringing in my ears and forgetfulness, but skin looks better and my balance is better. There’s much more, but not enough space here. From my research, I do not believe the RDA levels are adequate. Each of us is different–one may need 1000mg a day, yet another could get by with 500mg extra.
      Mg helps calcium be absorbed better and their are differences in calcium and magnesium. OTC supplements do not have any laws controlling them; therefore, they do not necessarily have in the pill what is on the label. That was another amazing fact which I thought was absurd. My patients used Nature Made so that’s what I bought the first time. I’ve tried several others, but Nature Made seems to be the best so far. I buy Mg and K+ I need OTC and use Nutrilite for all my supplement needs. They are organic and trustworthy. They have a line for children, but you still need to talk to his pediatrician. That was my last surprise–both my GP and neurologist have recommended various supplements for me to take. Most doctors don’t know any more about vitamins than the man in the moon. is a good place to check if you want to know about the quality of a vitamin brand. They do charge a membership fee. Back when you could check for free, Nutrilite was #1 or 2.
      Remember also, if the med directions tell you not to take with milk, you need to take the calcium supplement at a different time.

  3. Figs are also good source of calcium, I think best way to get it in babys diet. Hepls with constipation as well ???

  4. Dairy is not a good source of calcium. there is not enough magnesium in dairy and also too much protein in dairy. greens are the best source of calcium without any side effects unlike dairy. just add them to your salads as well as steam them with your veggies. also concentrate on potassium, magnesium, silica, vitamin D as calcium is not the end all in bone health and management

  5. I was going to take a calcium/magnesium supplement with this next pregnancy to hopefully minimize my chances of getting pre-ecclampsia. I was borderline towards the end with my first one. I have rheumatoid arthritis and was told I have a higher chance of developing it with that. My rheumatoid arthritis has gotten a lot worse since my first. What are your thoughts on that?

  6. Great post. Interestingly, the bioavailability of calcium in brassica vegetables is higher than that in dairy products – 61% of calcium found in broccoli is absorbable, compared with only 32% of that in milk. The reason remains unknown. Only 30–40 per cent of the calcium present in other food and drinks is absorbed. Some types of dietary fibre (phytates from wheat in unleavened bread e.g. chapatti) also bind calcium in the bowel to form an insoluble, non-absorbable salt. High-fibre diets, which speed the passage of food through the bowels, will also reduce the amount of calcium absorbed. I do prescribed calcium PLUS vit D for patients with osteoporosis.

  7. I have heard about the downside of taking calcium supplements before. (not from my doctor for sure). I am wondering, I suffer from bouts of Vertigo. My doctor told me I have calcium deposits near my inner ear and have to wait for them to dislodge on their own and through certain exercises. Is this due to calcium in my body being stored in the wrong place? Also, aren’t those little hard bumps that people get on their faces calcium deposits? I don’t take calcium supplements on a regular basis.

  8. Ok so I take calcium 50th daily but I also take magnesium and vitamin D3. I don’t eat a lot of dairy nor do I eat fish or many other things with the bone in. Should I continue to take the calcium or find another way to get what my body needs. I originally started taking it because I didn’t want my teeth to rot out from having babies.

  9. On my gynocolgist’s recommendation, I took calcium supplements for 3 years, even though I get lots of calcium in my diet and also lift heavy weights. The kidney stones last August more than convinced me to stop those supplements.

    Looking back, I should have insisted on a bone density scan before accepting her recommendation. As the scan showed, my bones are just fine and will continue to be just fine as long as I get calcium in my food and lift weights.

    Strongly recommend you question your medical practioners’ habit of recommending various supplements (or even prescriptions), if they didn’t do any tests first that show you actually need it. Had I done so, I would not have gone through some very serious pain.

  10. I think it is great that you personally get your vitamin D from the sun. For so many years I thought that was definitely the best source possible, but I found out recently that I am really deficient and read an article (which I can’t find), that the sun alone is not enough for most people. I just found this interesting, since I live in one of the sunniest places and am still deficient. I know there are a lot of factors that play into this, but I think everyone should talk to their Doctor about getting tested for Vitamin D levels regardless of how much sun they get.

  11. I had an endocrinologist tell me at Mayo Clinic to take calcium supplements for my bone issues. He told me none of it was in my urine. After reading the calcification, this scares me. Heart disease is very prevalent in my family history. My Mom just had 6 bypasses last year at 61. When I questioned this endocrinologist about what type of calcium to take and with what to take it with, he could not tell me. Scary how little real advice we get these days.

    • My ND told me calcium citrate is a better choice for a calcium supplement, it’s more readily absorbed by the body then something like calcium carbonate

  12. strange thing , istarted taking hcl and now when i drink my raw milk i don’t have stomach issues .

  13. I remember reading a study of vegans that if their dietary calsium intake was lower than 525mg a day their bones would be more likely to break. To me that indicates that yes we need calsium for healty bones, but not as much as usually is considered optimal intake. For most of us when we eat normal diet (some milk product, lots of vegetable, meat, and so on) we do not need to take supplements for calsium. If we are on limited diet were we cannot eat balanced diet it would not just be calsium that we should think about getting for the jar. I feel that it is allways better to get things (vitamins, minerals and so on) from food because there they are in natural for and have things around them we usually need to proces them.

  14. your article is good for pregnant ladies as well as babies. I wish you provide more calcium and iodine based products. I will definitely suggest to my known to visit this site….

  15. Ok so i am taking 500 in calcium and 500 in magnecium plus vitamin D3 2000 as suplement. I do have a healthy diet … is that too much intake daily ??

  16. what about eggshell powder? Is that a good form of calcium not associated with heart diseases?

  17. I had heard of this before and stayed away from calcium supplementation. BUT… My practitioner suggested a liquid Cal-Mag with other co-factors and it totally helped with some symptoms I was having. I try to get nutrients from food instead of supplements. I was eating lots of calcium rich foods and still had deficient levels.

  18. I have a question: I’ve know about regular calcium supplements not being good for you, but was told to take “coral calcium” – that it is much easier for your body to assimilate. Is that not true? I’ve been taking that for quite a long time… hmmmm. Would be much cheaper not to! We thankfully are able to get raw milk, so should I ditch the supplement?!

  19. Dr Wallach on you tube has much to say about calcium and most minerals
    He has been a nominee for Nobel prize in nutrition and has studied animal and human deficiencies and deceases accredited to those
    Therefore he is a supreme authority now on a mission to promote necessary supplementation since food sources are at the least questionable sources of good nutrients today. He has helped heal people from various modern diseases just by supplementing. Very interesting material exposing modern medicine as sleeping with big Pharma for business. I use his supplements daily and feel much livelier
    God bless

  20. Love the article, I’m going to have to book mark it and share it with others. I’ve never been a milk drinker and always ate limited dairy, learned after my first was born that I’m actually dairy sensitive. Since I’m dairy limited and don’t take calcium supplements (it feels like that’s the only supplement I don’t take) I always get asked “aren’t you worried you aren’t getting enough calcium?”. I’ve never worried and this article helps me worry even less. When I was tested during both pregnancies all my vitamin levels were well within normal, even my second pregnancy that I nursed my first daughter through.

    I’ve read (wish I could remember the source) that breastfeeding, especially “extended” breastfeeding is actually really good for preventing osteoporosis. It had to do with minerals being pulled from your bones while breastfeeding but when you stopped all the minerals are restored and your bones are left stronger than before. Have you heard this? Ill try to find a source and post it.

  21. 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. : )

  22. 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.

  23. 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!!

  24. 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?

  25. 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!

  26. 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. 🙂

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

    • 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.

  28. 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.

  29. 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.

  30. 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.

    • 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.

  31. What are your thoughts on egg shell water?

  32. 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?

  33. 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!!

  34. 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

    • 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