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Calcium Is Calcium – Or Is It?

If you’ve had an ongoing interest in alternative health and supplements, you’ve probably heard an expression that regularly gets thrown around – “calcium is calcium.”

I’ve heard store staff say this when asked to recommend a particular product – which translates to “just pick the cheapest one.” And doctors often repeat this if asked by a patient which product they recommend:

“I tell my patients to take the kind that they tolerate best and is least expensive,” Marcy B. Bolster, MD, professor of medicine in the division of rheumatology and immunology at the Medical University of South Carolina and director of the MUSC Center for Osteoporosis and Bone Health. (1) It’s simple, and provides easy to follow advice for those shopping for the world’s most purchased mineral.

But is it accurate? Yes and no.

Once “Free”, All Calciums Are Equal

Marcy B. Bolster, MD is advising you to buy the cheapest calcium as she knows all calciums are equal – on a molecular level. But the thing is you can’t purchase calcium on a molecular level!

Calcium always comes to you packaged within rock, shell, bone, coral or plant- and those sources are all definitely different from each other.

Once it breaks down, the ingredients in a supplement travel from your intestine to your bloodstream. During the journey the calcium ion detaches itself from the carbonate or citrate it is initially attached to. Once in the bloodstream it becomes ionized calcium.

Ionized calcium is calcium that is freely flowing in your blood (also called free calcium) and not attached to proteins. Once the calcium in your supplement becomes ‘free’ ionized calcium in your bloodstream, then yes, ‘calcium is calcium’; it’s efficacy is equal.

But there are many ‘layers’ of a supplement- and that is where the quality and performance differences lie.

The Best is Never Free – or Equal

For starters, the supplement you choose dissolves gradually in your stomach at a speed either faster or slower than competing products, depending on whether it’s a tablet or capsule, and whether it’s made with binding agents or not.

Tablets typically use binding agents (which act like glue), and are extremely heat pressed- which both interfere with dissolution, and contribute to bloating and constipation.

As you would expect, calcium tablets or capsules from plant are much more body friendly, dissolve much quicker and are more tolerable than all the other calciums from rock, bone etc and.

Another difference is plant, rock or bone all contain different amounts of elemental calcium (from 40 to 18%). That’s why some products require only one pill a day, and others 5 or more, to reach the same target of say, 1000mg.

But it’s worth remembering that, although one-a-day 1000mg tablets are convenient, they are ineffective, as countless studies show we can’t absorb any more than 500-600mg of calcium at once….

…So it would be wise to avoid one-a-day calcium products.

And avoid low level calciums that require taking handfuls of capsules per day- because the stats show we tire of that, and fall off the program.

Which Calcium Does Your Heart Prefer?

International headlines in the last 2 years warned that clinical studies prove that calcium supplements, with or without added vitamin D, can increase your risk of heart attacks. Not surprisingly, the participants were taking large amounts of single element, rock sourced calciums.

Without necessary co-factors of vitamin D, K2 and various trace minerals, the calcium ended up in participants’ arteries, leading to more health problems than were solved.

Bones Are Complex- And So Should Be Your Supplement

Another quality difference is most calcium supplements contain only calcium, or have maybe added vitamin D. But human bones are made from much more than calcium. Magnesium, manganese, silica, strontium and several other trace minerals make up bone, and therefore should be mandatory in the supplement you take. Very few formulas take this into account however.

So it is not surprising that typical single element calcium supplements, from rock, shell, or bone- either with or without added vitamin D, are clinically supported to only slow bone loss, not increase bone growth.

Calcium Conclusion

Shopping for the cheapest supplement with the mindset that “calcium is calcium” is tantamount to buying the cheapest PC because they all share the same Intel chip inside.

You wouldn’t do that, because you know that screen size, memory and many other factors make one computer definitely ‘better’ than another, despite having an Intel chip as a common point.

And the same is true for calcium supplements- on a molecular level the calcium inside is equal. But many other factors add up to determine which supplement performs better than another.



Author: Monica Straith, BS

Monica is the PR and Outreach Manager and Fitness Lead at AlgaeCal. She’s an ACE Certified Personal Trainer and Nutrition Specialist, and has a B.S. and B.A. from the University of Wisconsin-Madison, where she played varsity soccer for four years. Monica pulls from her experience in athletics and health to contribute to AlgaeCal and has also been featured on myfitnesspal blog, Prevention, and Huffington Post.