What Does Science Really Say About Getting Enough Calcium?


The data is shocking:

  • More than 50% of Americans and between 24% – 60 of Canadians and take dietary supplements of some type on a regular basis. (1)
  • 43% of all people and nearly 70% of post-menopausal women in the U.S. take calcium supplements. (1)
  • In the U.S. and Canada, more than 70% of calcium comes from dairy products like cheese, milk, yogurt and processed foods made up of calcium; such as, ice cream, lasagna, and pizza. (1)
  • Yet, the National Osteoporosis Foundation reports that 54 million Americans are still affected by osteoporosis and low bone mass. (2)

The data just doesn’t add up. Haven’t we been told that calcium supplementation is necessary to prevent osteoporosis, and that “milk does our bodies good?” With multibillion supplement and dairy industries behind the scenes, it’s got to make you wonder what does science really say about getting enough calcium?


The Calcium Lie

One of the most misleading claims that have driven people to purchase supplements is the idea that bones are made of calcium. Although not entirely false, it is only partly true. In fact one-twelfth true!

As described by Robert Thompson, MD in his book, “The Calcium Lie: What Your Doctor Doesn’t Know Could Kill You.”

If you believe that bones are made of calcium, you have subscribed to The Calcium Lie. You’re not alone. Most consumers and, surprisingly, most doctors, believe that bones are made of calcium. Yet any basic biochemistry textbook will tell you the truth: Bones are made of at least a dozen minerals and we need all of them in perfect proportions in order to have healthy bones and healthy bodies. (3)

Thompson claims that not only is total nutrition balance key for bone health, but

Including obesity, Type 2 diabetes, Type 2 hypothyroidism, hypertension, depression, problem pregnancies and more.”

Relationship with Other Nutrients (4, 5)

The reason that excessive calcium intake can lead to a slew of health challenges is because it offsets the vitamin and mineral balance that we were designed to enjoy. Here are just a few ways that calcium is intimately connected with other nutrients in our body:

  • Vitamin D and calcium go hand-in-hand. Many foods that contain one also contain the other, and they clearly work together in bone health. For example, vitamin D promotes calcium absorption from the digestive tract and helps maintain proper serum calcium levels throughout the rest of our body. Vitamin D is crucial for normal bone mineralization and prevents bones from getting brittle or thin.
  • Phosphorus competes with calcium for absorption in the intestine, and the typical Western diet provides too much of it. This can lead to reduced body storage of calcium and possibly calcium deficiency.
  • Likewise, phosphates – natural salts containing phosphorus – found in pre-packaged meats, sodas and baked goods compete against calcium for absorption in the intestines.
  • Iron, magnesium and zinc are also known to compete with calcium for absorption. Although, this doesn’t seem to be a problem up to 1,500 mg per day. For people routinely consuming more than 1,500 mg of dietary calcium per day, it is advisable that they boost their iron, magnesium and zinc supply as well.
  • Excess sodium can cause calcium to be lost in the urine. This is a significant issue for most Americans, whose standard diet ranges from 4,000 – 5,000 mg of sodium per day; which is almost 4 times more than the 1,100 – 2,400 mg recommendation. To help offset this, especially in light of our Western diets rich in table salt, 1,000 mg of calcium is recommended today for most adults. More on daily recommended values (DRV) below.
  • Protein and calcium have a more complex relationship than the nutrients listed above. Diets rich in protein, for instance, increase stomach acid production and can potentially optimize calcium absorption in the intestines. Diets rich in protein can also increase the loss of calcium in the urine similarly to sodium. When protein-rich diets become excessive, calcium balance will most certainly be disturbed.
  • Alcohol leads to loss of calcium in the urine similar to sodium and protein-rich diets, although this amount is suspected to be marginal for most people. It has been reported that long-term alcohol abuse is a separate risk factor in-an-of-itself for bone loss, because it disrupts the hormones that control calcium blood levels.
  • Phytates – antioxidant compounds found in legumes, nuts, seeds and whole grains – are also known to impair calcium absorption. Highlighting that bone strength has many more layers to it, it has been shown that diets high in phytates are linked to an increase in mineral bone density.

From this short list, it should be pretty clear that osteoporosis and bone weakening is not about calcium deficiency, but an imbalance of the total nutritional content in our bodies.

Calcium Supplementation Research

At the core of the calcium debate is the presupposition that “Americans very frequently fail to get the daily recommended intake of calcium.” (4) Paradoxically, how can we be “calcium deficient” when most of us are either supplementing with calcium pills or consuming foods like fortified bread and milk on a regular basis? Granted, the nutrient imbalances described above can play a role in this equation, but what about taking a closer look at the supplements themselves?

According to an article published in the journal Kidney International, “Calcium supplements for prevention and treatment of mineral and bone disorders in chronic kidney disease (CKD) have been alternately praised and damned. Clinical evidence in favor of either attitude has been lacking.” (6) Written by Belgian researchers out of the University Hospital Leuven, the article outlines some critical information that everyone must get a handle on before jumping on the calcium supplementation bandwagon.

Most importantly, calcium supplementation has been linked to health disorders because synthetic calcium typically comes from limestone and rock, not fresh plant sources. (7) Causing calcification of arteries, the conclusion of a 2010 groundbreaking meta-analysis evaluating 15 clinical trials and 20,000 patients published in the British Journal of Medicine claims that,

Calcium supplements (without co-administered vitamin D) are associated with an increased risk of myocardial infarction. As calcium supplements are widely used these modest increases in risk of cardiovascular disease might translate into a large burden of disease in the population. A reassessment of the role of calcium supplements in the management of osteoporosis is warranted. (8)

This article is one of the reasons why you’ll typically find calcium supplements paired with vitamin D and drug stores and supplement shops.

Interestingly, a study published the next year by the same researchers explained that these findings were incomplete. A follow-up to the seven year, 36,282 participant Women’s Health Initiative Calcium/Vitamin D Supplementation Study revealed that personal calcium supplementation at the time patients were randomized into test groups had more of an effect on the actual experiment than originally anticipated. Shocked, they learned that 54% of the women were taking personal calcium supplements after reviewing the records.

After taking into account this widespread use, the researchers discovered that, “

“Especially myocardial infarction.” (9) The confusion was that,

“In women taking personal calcium supplements at randomization, the addition of calcium and vitamin D did not increase cardiovascular risk, and the risk of cardiovascular events with calcium and vitamin D was also not affected by the dose of personal calcium supplements. This suggests that there may not be a dose-response relationship between calcium supplements and the risk of cardiovascular events. Thus, even doses of <500 mg/day might be associated with an increased risk of cardiovascular events similar to doses ≥1000 mg/day. This would be consistent with the notion that the abrupt change in plasma calcium concentration after supplement ingestion causes the adverse effect, rather than it being related to the total calcium load ingested.” (9)

In laymen’s terms, this is saying that, regardless of the amount and type of calcium supplementation you are taking, the damage done to the cardiovascular system happens immediately. Considering the countless millions of men and especially post-menopausal women who faithfully take calcium every day, this is pretty scary, huh?

Top 9 Calcium Sources in Food

I’ve been asked whether or not plant-based calcium supplementation is the way to go because more synthetic versions manufactured from rock are harmful. From what we just learned from the scientific literature, a supplement is supplement, regardless of its origin. The problem with taking a plant-based supplement is that it still puts you in the position where you will develop vitamin and mineral imbalance.  At the end of the day, there’s nothing more effective as getting your calcium from the original, plant- or animal-based source in its natural form!

The thought that we need to drink pasteurized, homogenized cow’s milk or consume a manmade supplement (regardless if it’s plant-based or not) to get our daily dose of calcium is quite absurd. Common sense tells us that cows get calcium from grass. Then, we should be able to get our calcium from green leafy veggies, right?  According to the George Mateljan Foundation, the best sources of calcium are, in fact, not dairy at all! (4)

  • Sardines (3.2 oz): 35% daily recommended value
  • Sesame seeds (1/4 cup): 35%
  • Collard greens (1 cup): 27%
  • Spinach (1 cup): 24%
  • Turnip greens (1 cup): 20%
  • Mustard greens (1 cup): 17%
  • Beet greens (1 cup): 16%
  • Bok Choy (1 cup): 16%

Comparatively, dairy sources like yogurt (30%), cow’s milk (14%) and cheese (20%) just aren’t worth the risk if they are pasteurized and not organic. They are loaded with hormones that are suspected to cause pre-mature puberty and even cancer. (10, 11)

Calcium Recommended Daily Allowance

According to the National Academy of Sciences Institute of Medicine, you will want to get the recommended daily dose of calcium to prevent a negative calcium balance. (1)

  • Children 1-3 years old: 700 mg
  • Children 4-8 years old: 1,000 mg
  • Children 9-18 years old:  1,300 mg
  • All adults 19-50 (including pregnant/lactating women): 1,000 mg
  • Women 51 to 70: 1,200 mg
  • Men 51 to 70: 1,000 mg
  • All adults 71 and over: 1,200 mg

A Note About Milk

There’s a movement out there claiming that certain types of milk, A2 milk specifically, is the “healthy” version and can be consumed with great benefit even if pasteurized. Initially, I thought that this was the case, but after revisiting the topic, I have discovered that the research doesn’t always support this theory. Here’s some of the most up-to-date information on A2 milk:

A2 cow’s milk contains only the A2 type of beta-casein protein, not the more common A1 protein that is normally found in milk. Branded by the A2 Milk Company, A2 milk is sold mostly in Australia, New Zealand and the United Kingdom. No one really heard of A1 or A2 milk until early 1990s, when researchers claimed to have solved the “milk problem.” That is, if milk does a body good, then why is there is a direct connection between developing autoimmune disorders like type I diabetes and milk consumption? (12) A2 Corporation supposedly proved that it was because of A1 proteins from specific cow breeds, and that they cracked the code in New Zealand.

Since then, after careful investigation, it seems that the A2 Corporation’s theory was just a tad bit ambitious. In the words of a 2005 article published in the European Journal of Clinical Nutrition,

The A1/A2 milk hypothesis was ingenious. If the scientific evidence had worked out it would have required huge adjustments in the world’s dairy industries. This review concludes, however, that there is no convincing or even probable evidence that the A1 beta-casein of cow milk has any adverse effect in humans.

This review has been independent of examination of evidence related to A1 and A2 milk by the Australian and New Zealand food standard and food safety authorities, which have not published the evidence they have examined and the analysis of it. They stated in 2003 that no relationship has been established between A1 or A2 milk and diabetes, CHD or other diseases. (12)

The bottom line is this: while the company marketing A2 milk claims that milk containing A1 proteins are harmful, there is little to no scientific evidence that A2 milk has benefits over normal milk. (13, 14)   Some people may indeed do better with A2 milk as opposed to A1 milk – but we’ve still got a lot to learn about why this is.  It is my personal recommendation to steer clear of all dairy products unless they are certified organic and raw. This way you’ll make sure that the necessary enzymes are in it and that you’re getting a healthy supply of calcium.

At the end of the day, the research is clear. Calcium supplements are more trouble than they are worth and the best way to normalize your calcium levels is to eat a diet balanced in all of your vitamins and minerals.


Dr. B.J. Hardick

About Dr. B.J. Hardick

Dr. B.J. Hardick is a Doctor of Chiropractic and internationally-recognized natural health author and speaker. His health journey began as a child — alternative medicine is the only medicine he has ever known. In 2009, he authored his first book, Maximized Living Nutrition Plans. In 2018, he authored his second book, Align Your Health. An energizing and passionate speaker, Dr. Hardick shares his lifestyle methods to numerous professional and public audiences every year in the United States and Canada. His teachings encompass the principles of ancestral nutrition, detoxification, functional fitness, mindfulness, and green living. Learn More