Complicated Calcium Confusion: What’s the Best Source of Calcium?

I can honestly say that I have never been a fan of calcium supplementation.  Or at least maybe not for the last decade or so.

It has truly been that long since the medical research began to change its opinion on using calcium supplements to strengthen bones.  This is not to say that I don’t recommend calcium supplements, but it is a pretty rare situation and only when someone has been diagnosed (in our office or elsewhere) with severe osteoporosis.  It has been a long, long time since I recommended calcium for anyone just to “build strong bones.”

Before we go any further, I do need to clarify something about calcium supplements for bone health.  Tums are NOT a calcium supplement.  It is a toxic product containing aluminum and artificial colors and should never, ever have been recommended to support bone health.

Any calcium supplement used for bone health should be a bone support formula, containing not only calcium, but other bone-supporting components like magnesium, boron and zinc.  And the best form of calcium is NOT calcium carbonate.  Higher quality forms like citrate are the preferred forms–especially when it matters.

Another thing that you may not realize is that your body is very selective as to how much calcium it will absorb at any given time.  This is because calcium levels are very tightly regulated in the bloodstream.  Too much or too little calcium can be fatal.  As in rigor mortis, the ultimate calcium deficiency in the bloodstream.  To keep this level constant, the gut keeps a very tight grip on how much calcium is absorbed at any given time.  If you decide to down an entire bottle of calcium supplements at a single time, the gut will actually push back, resulting in even lower amounts of calcium being absorbed.

This is why, when you are taking calcium supplements, you should take them spread out throughout the day as much as possible.

But none of this really matters because of one important fact.

Vitamin D plays a very large role in regulating the amount of calcium you gut will absorb (it’s role is much bigger, but for the purposes of this particular line of discussion, this will suffice).  With low levels of vitamin D (an all-too common problem in todays’ sun-fearing society) more calcium may not be enough to get the job done.  On the flip side, having enough vitamin D flowing through your blood will make taking a calcium supplement pointless on top of a good quality diet.

Unfortunately, for years, doctors were telling their patients to take calcium supplements (frequently in the form of Tums) and given no recommendations on vitamin D.  While that is changing, this particular study demonstrates how backwards this recommendation is.

In the study, researchers looked at 3448 men and 3812 women who were older than 50 years of age and broke them down into daily dietary calcium intakes of (1) less than 400 mg/d, (2) 400–799 mg/d, (3) 800–1199 mg/d, and (4) 1200 mg/d or greater.  Overall, the average daily calcium intake was 470 mg/d.

They then measured bone density and compared it to average daily calcium intake.  Here’s what they found:

  • Those with calcium intake less than 400 mg/d had lower bone density (specifically, femoral cortical thickness and buckling ratio).
  • In men, bone density was higher in those with calcium intakes up to 1200 mg/d.
  • Importantly, these interactions disappeared when the 25-hydroxyvitamin D level was over 30 ng/mL (men) or 20 ng/mL (women).

So, while it can be argued that calcium is important for bone health, it pales in comparison to the effect of vitamin D, so much so that adequate (not even optimal) levels of vitamin D essentially protect against low calcium.

That’s not to say that you should deliberately deprive yourself of calcium while taking vitamin D just to see if it pans out.  Rather, a solid diet with good calcium sources combined with vitamin D supplementation (starting at 2,000 IU / day) is the best way to go.  Solid sources of dietary calcium include:

  • Spinach and kale
  • Okra
  • Collards
  • Soybeans
  • White beans
  • Some fish like sardines, salmon, perch, and rainbow trout
  • And there are foods that are calcium-fortified, such as soy milk, some orange juice, oatmeal, and breakfast cereal

You might notice the suspicious lack of dairy on the list.  If you’re a regular reader of the Rantings you’ll know that I’m not a fan of dairy.  Enough so that I compiled an eBook of research demonstrating that dairy is not the health food that we think it is that can be found by clicking here.


James Bogash

For more than a decade, Dr. Bogash has stayed current with the medical literature as it relates to physiology, disease prevention and disease management. He uses his knowledge to educate patients, the community and cyberspace on the best way to avoid and / or manage chronic diseases using lifestyle and targeted supplementation.