The Truth About Calcium Supplements

Written by Andy Mobbs
Reviewed by Erica Lee, RN
Featured image for article on calcium supplements

If you’re taking calcium supplements, do read this article until the very end. New research shows calcium supplements don’t work and may even be dangerous! Find out why this is so and what to do about it instead.

Why do people take calcium supplements anyway?

Around 30-40 years ago, doctors began to tell their elderly patients to take calcium supplements on a regular basis to combat the effects of bone loss due to aging. It was the most logical thing to do, as bones are made up of minerals and proteins. More specifically, the mineral content of bones is 64% calcium and 99% of the body’s calcium is in our bones and teeth.

But what do the recent studies on calcium supplements say?

40 years later, the latest research is showing that calcium supplements are not as beneficial as initially thought. Here’s why:  

It does not slow or stop bone loss

Increasing calcium intake either through diet or supplements does not slow or stop bone loss. Neither does it prevent falls or fractures in older men and women (1, 2).

It can lead to health issues

Taking too much calcium supplements can actually cause health problems, such as kidney stones (3) and heart disease. It can also increase the risk of heart attacks and stroke.

The body needs calcium to survive

It increases the risk of heart attack and heart disease

A study published in the British Medical Journal (BMJ) focused on evaluating the link between dietary calcium intake and calcium supplementation with heart attack risk. It followed 23,980 men and women, aged 35-64, for a total of 11 years. They found that people who took calcium supplements had a greater risk of heart attack compared to those who just got their calcium from their diet (4).

Another article in the BMJ reviewing other studies done on over 12,000 people showed that people who took calcium supplements had an increased risk of heart attack, stroke and death (5).

Furthermore, a study published in the Journal of American Medical Association – Internal Medicine found that taking over 1000 mg calcium supplement per day led to an increase in the risk of death from heart disease (6).

Instead of calcium supplements, eat calcium-rich foods instead

Does it mean we need to avoid calcium now?

No, absolutely not. What the latest studies are saying is certainly an eye-opener, especially considering that we were told to take calcium supplements for our own good! However, there’s no need to be afraid.

The research is not saying that dietary calcium is not beneficial (our bodies need calcium, after all). It’s saying that supplementing dietary calcium with additional calcium from pills is where we can potentially run into problems and get into trouble.

The additional / excess of calcium from supplements can cause a sudden burst of calcium in the blood. This can get embedded in our arteries leading to plaque formation. Over time, these plaques can enlarge and clog the arteries, which then restricts the blood flow, either partially or completely.

The good news is that dietary calcium is absorbed differently, slowly and in smaller quantities, so it does not have the same effect (7).

The calcium and magnesium link

Increasing our calcium intake via supplements can upset the natural balance between calcium and magnesium. Like calcium, magnesium has many functions in our body, including maintaining the balance between calcitonin and the parathyroid hormone. So, what do these 2 hormones do?

  • Calcitonin – decreases the calcium levels in the blood by preventing bone breakdown
  • Parathyroid hormone – increases calcium levels in the blood by increasing bone resorption and preventing calcium from being deposited into bones

In short, too much calcium inhibits magnesium absorption. Without enough magnesium to balance calcitonin and the parathyroid hormone, there will be less calcitonin and more parathyroid hormone, consequently causing our bones to lose their density and hardness.

Milk is naturally rich in calcium

Why we’re not getting enough magnesium…

Even without excess calcium intake to inhibit magnesium, the majority of us do not get enough magnesium on a daily basis. In fact, on average, we are only getting 68% of the recommended daily value of magnesium (8). Here are a few reasons why most of us are not getting enough magnesium:

It’s been taken out of our food

In order to obtain more quantities and varieties of fruit and vegetables, the crops are growing quicker, but spending less time in the ground to absorb the necessary nutrients. Thus, even the “good stuff” we buy from the supermarkets has significantly less magnesium / essential nutrients than 30-40 years ago (9). Magnesium has also been taken out of our salt and filtered out of our water.

Stress of modern life

In addition, the sustained stress of our daily lives leeches our body of magnesium and reduces our gut’s ability to absorb magnesium.

Lack of understanding regarding magnesium’s benefits

Combined with the reduced availability of magnesium, most doctors also do not understand the importance of magnesium in bone health. In fact, many doctors still believe that people should consume at least twice as much calcium as magnesium.  However, this belief is based on false information.

Back in 1989, the French researcher Dr Jean Durlach suggested the 2:1 calcium to magnesium ratio as an extreme that should never be exceeded. However, this was misunderstood, and it has now become thought of as the ‘norm’ (10).

In reality, we should be aiming for a ratio of 1:1. However, the average diets today have much more calcium than magnesium. If you consume additional calcium supplements, it will increase the ratio to 4:1 or 5:1! We know from the previously mentioned studies that this isn’t beneficial to our health. Fortunately, there is an easy solution to this and that is to swap the calcium supplements for magnesium supplements.

Eat healthy and nutritious food

Magnesium and higher bone density

One of the leading risk factors for developing osteoporosis is magnesium deficiency (8). Several studies with large populations of both men and women have found that those with higher magnesium intake have a higher bone density (11). Also, another study has found that postmenopausal women with osteoporosis have lower blood magnesium levels than healthy postmenopausal women (12).

Direct studies on increasing magnesium intake either through diets or supplements and its effects on bone density and osteoporosis are still relatively few in number due to the traditional focus on calcium. However, most of the available studies have shown that increasing magnesium intake can increase bone mineral density in postmenopausal women (13).

One particular small/short-term study found that just by taking 1830 mg of magnesium citrate for 30 days in 10 postmenopausal women with osteoporosis had less bone loss compared to the placebo group (14).

Instead of calcium supplements, take high absorption magnesium

It is essential to recognize that a limitation within the available studies is that researchers have used magnesium citrate or oxide as the supplement. Unfortunately, they are NOT the highest quality nor the most easily absorbed magnesium available.   

Intelligent Labs MagEnhance magnesium supplement

With more recently developed maximum absorption supplements like our Magenhance Magnesium Complex, the potential benefits on bone density are much greater.

Magnesium is great for the heart and immune system. It improves sleep, helps you feel calm, relieves aches and pains, and even promotes insulin sensitivity.

To sum up this post, there is no downside to trying a magnesium supplement for yourself. And unlike calcium, magnesium is a much safer supplement to take!


(1) Tai V, Leung W, Grey A, Reid IR, Bolland MJ. Calcium intake and bone mineral density: systematic review and meta-analysis. BMJ. 2015 Sep 29;351:h4183

(2) Bolland MJ, Leung W, Tai V, Bastin S, Gamble GD, Grey A, Reid IR. Calcium intake and risk of fracture: a systematic review. BMJ. 2015 Sep 29;351

(3) Jackson RD, LaCroix AZ, Gass M, Wallace RB, Robbins J, Lewis CE, et al. Calcium plus vitamin D supplementation and the risk of fractures. N Engl J Med2006;354:669-83.

(4) Kuanrong Li, Rudolf Kaaks, Jakob Linseisen, Sabine Rohrmann, Associations of dietary calcium intake and calcium supplementation with myocardial infarction and stroke risk and overall cardiovascular mortality in the Heidelberg cohort of the European Prospective Investigation into Cancer and Nutrition study, BMJ Volume 98, Issue 12

(5) Bolland MJ, Avenell A, Baron JA, Grey A, Maclennan GS, Gamble GD, et al. Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis. BMJ2010;341:c3691.

(6) Qian Xiao, PhD; Rachel A. Murphy, PhD; Denise K. Houston, PhD; et al, Dietary and Supplemental Calcium Intake and Cardiovascular Disease Mortality, JAMA Intern Med. 2013;173(8):639-646.

(7) Ian R Reid, Mark J Bolland, Calcium supplements: bad for the heart? BMJ,

(8) Rude RK, Singer FR, Gruber HE. Skeletal and hormonal effects of magnesium deficiency. J Am Coll Nutr 2009;28:131–41.

(9) Donald R. Davis, Declining Fruit and Vegetable Nutrient Composition: What Is the Evidence? HortScience February 2009 vol. 44 no. 1 15-19

(10) Durlach J. Magnes Res. 1989 Sep;2(3):195-203. Recommended dietary amounts of magnesium: Mg RDA.

(11) Tucker KL. Osteoporosis prevention and nutrition. Curr Osteoporos Rep 2009;7:111-7.

(12) Mutlu M, Argun M, Kilic E, Saraymen R, Yazar S. Magnesium, zinc and copper status in osteoporotic, osteopenic and normal post-menopausal women. J Int Med Res 2007;35:692-5.

(13) Institute of Medicine (IOM). Food and Nutrition Board. Dietary Reference Intakes: Calcium, Phosphorus, Magnesium, Vitamin D and Fluorideexternal link disclaimer. Washington, DC: National Academy Press, 1997.

(14) Aydin H, Deyneli O, Yavuz D, Gözü H, Mutlu N, Kaygusuz I, Akalin S. Short-term oral magnesium supplementation suppresses bone turnover in postmenopausal osteoporotic women. Biol Trace Elem Res 2010;133:136-43.

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