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…
- 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.)
- 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?
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.
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
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?!
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.
what about eggshell powder? Is that a good form of calcium not associated with heart diseases?
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 ??
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….
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.
strange thing , istarted taking hcl and now when i drink my raw milk i don’t have stomach issues .
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