Do Calcium Supplements Increase Heart Attack Risk?

Many of you have been asking me about recent headlines
saying that calcium supplements may boost heart
attack risk.

You’re asking me “What’s up with that?” “I thought
calcium supplements were good for me.”

Let’s forget the hype and start by looking at the
study itself.

The actual study was published online in the British
Medical Journal on July 29, 2010 (M.J. Bolland et al,
BMJ, 341: c3691). It was a meta-analysis, which
combines the results of multiple clinical studies, and
is generally considered to be a very strong way of
analyzing the data from published clinical studies.

However, the validity of a meta-analysis is limited by
the studies that it excludes. You can come to a very
misleading conclusion if you exclude too many perfectly
valid studies.

In this case the authors excluded all studies using
calcium supplements containing vitamin D because, as
the authors stated in their paper, “vitamin D
supplementation has been associated with decreased
mortality”.

I think you can see where the authors were trying to go
with this study!

And with this exclusion criterion, their meta-analysis
only included 15 out of 11,363 clinical trials of
calcium supplementation.

And, it wasn’t only vitamin D that was excluded. A
brief review of available supplements shows that when
you exclude vitamin D you also exclude magnesium,
vitamin K and all of the other nutrients needed for
bone formation.

What you are left with is just calcium alone – calcium
carbonate, calcium citrate, calcium phosphate,
“chelated” calcium or some combination of the four.

“What’s wrong with that?” you might ask.

It brings me to another one of my pet peeves. Most
companies evaluate calcium supplements by how much
calcium gets into the bloodstream – not how much of
that calcium gets into the bone.

Those of you who have been around for a while may
remember a time when doctors were saying “Forget about
those expensive calcium supplements. Just take Tums.”

After all, Tums (pure calcium carbonate) are cheap and
easily absorbed (a lot of the calcium gets into the
bloodstream). What’s not to like?

The short answer is plenty!

To help you understand why, let me start by reminding
you of a study that Shaklee commissioned a number of
years ago. They asked Dr. Albanese of the University of
Albany to compare the effect of 800 mg of calcium from
calcium carbonate and 600 mg of calcium from Shaklee’s
Vita-Lea (Shaklee’s multivitamin supplement containing
vitamin D, magnesium, vitamin K, boron and all of the
trace minerals required for bone formation in addition
to the calcium) on bone density in post-menopausal
women.

His study showed that the 600 mg of calcium from
Shaklee’s Vita-Lea was twice as effective as the 800 mg
of calcium from calcium carbonate at preserving bone
density – and that study was published in the Journal
of the American Medical Society (You can check
Shaklee’s published list of clinical studies for the
exact reference)

We know that when you take a supplement containing
calcium alone (something like a calcium carbonate
supplement, for example) a lot of calcium is getting
into the bloodstream. That brings us to the really
important question:

If that calcium isn’t getting into the bone, where is
it going?

The answer is that some of it is excreted in your urine
– which is OK as long as you are drinking enough water
and getting enough magnesium and vitamin B6 to prevent
kidney stone formation.

But the rest of it is deposited in your soft tissue and
your arteries.

The calcium that is deposited in your soft tissue can
lead to inflammation and arthritis.

The calcium that is deposited in your arteries causes
hardening of the arteries, which can increase your
blood pressure and increase your risk of heart attack
and stroke.

So the bottom line is that getting a lot of calcium
into your bloodstream is not necessarily a good thing
unless that calcium is actually incorporated into your
bones – and supplements containing calcium alone are
only effective at getting calcium into the blood
stream.

The bottom line is that the study was accurate in
describing the safety of calcium-only supplements, but
the headlines should have read “BAD calcium supplements
may boost heart attack risk.”

My concern is there are literally thousands of clinical
studies showing that calcium supplementation increases
bone density and decreases the risk of osteoporosis.

The inaccurate reporting of the conclusions of this one
study may deter many people from taking the calcium
supplements they need to prevent the crippling effects
of osteoporosis.

To Your Health!
Dr. Stephen G Chaney