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Do Calcium Supplements Cause Heart Attacks?

It was my birthday last week while I was traveling, and in fact, I forgot about it until I started to get emails from Facebook letting me know my "friends" have posted birthday blessings to my page.

First, thank you. I truly appreciate the acknowledgement that I am a year older now.

However, please don't think I'm ignoring you. It's just that I haven't been on Facebook in years, literally. I don't know why, but I just can't get into the whole Facebook thing. I read a quote that summarizes: "Facebook is like jail -- you sit around and waste time, write on walls, and get poked by people you don't know." Well, maybe it's not THAT bad...but now you know why I may not respond through Facebook.

So, today I'm really excited because there's a newly published study I came across that blasts calcium supplements. Awesome! Why am I so excited? Because I get to expose how little these so-called educated researchers know about nutrition.

These researchers warn that the indiscriminate use of calcium supplements "should be abandoned," as their meta-analysis of 29,000 people suggests the risks of heart problems outweigh the potential benefits. This "new" data (but in reality, not new knowledge), published in the British Medical Journal, suggests that calcium supplements (with or without vitamin D) may increase the risk of heart attack by 25%, and the risk of stroke by 15%. The new findings back up the results of last year's meta-analysis that suggested calcium supplementation could have more risks than benefits. Here is a previous post where I make mention of the calcium study from last year.

When interviewed, Ian Reid, the senior author of the study said, "When we do the calculations from these 29,000 people, we find that for every thousand people we give calcium to for five years, we cause six heart attacks and we prevent three fractures."

Reid's previous study last year looked at calcium supplementation alone; however, since many people also take vitamin D, Reid and his team set out to see if their findings held true when this was taken into account.

Surprise, surprise! Of course, the results were similar...calcium supplementation increases the risk of heart attack and stroke.

Well, if you know me, or heard one of my presentations on the subject, you'll know what I'm about to say next. It's not the calcium supplements that are bad -- those at risk of osteoporosis, or those who have it, should definitely continue to take them. The problem is... yes, most people are not getting enough vitamin K, and more specifically K2.

Here's how it works (and again, you can post a question in the comments section and I can get into a lot more detail if you want), there are vitamin K-dependent proteins in the bones and the soft tissues, like the arteries. When these are activated in the presence of vitamin K, they can do their job with respect to calcium metabolism. In simple terms, vitamin K is what tells your body where to put all that good calcium.

Without enough vitamin K, your body will just throw calcium all over the place. When calcium is deposited in the arteries, it's called "arterial calcification," and this is now seen as the greatest predictor of a heart attack and stroke (more than cholesterol levels, blood pressure, etc.). This is called the "calcium paradox"--where calcium ends up in the soft tissues and arteries instead of the bones--and it's related to a vitamin K deficiency.

Osteocalcin is the protein produced in the bones. When it's activated by K, it pulls calcium into the bones. MGP (Matrix Gla Protein, the most potent inhibitor of soft tissue calcification currently known) is the protein for the arteries. When it's activated by K, it prevents calcium from being deposited into the arteries.

For this reason, it's MANDATORY for everyone taking a calcium supplement to also be taking a vitamin K supplement. Just the addition of this one essential nutrient, you ensure you're getting the most benefit from the calcium supplements, while preventing the negative side-effects of them.

Some "bone health" formulas will contain vitamin K, but most people just take a simple calcium or calcium-magnesium supplement. So make sure you check the ingredient list of your calcium supplement and if it doesn't contain vitamin K, go to the healthfood store as soon as you can and buy some K.

Update: Click HERE to check out the post on vitamin K deficiency that followed this post.

So, don't believe the hype. Here's an analogy to help you make sense of this... you buy a completely broken down car to repair, and think, "I know, it needs tires to run" (and you'd be right, partially). But you try driving the car and it doesn't even start because it has no engine or even gas, etc. It's obvious you need more than just tires to make a car go. Ian Reid`s interpretation of this would be, "hey, don't waste your money on tires...they don't make the car run." But without tires, you're not going very far...even if you've got a brand new engine and a full tank of gas. Get it?

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Reference: Calcium supplements with or without vitamin D and risk of cardiovascular events (full-text published study)

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  1. What dosage of vitamin K would you recommend? How much is enough?

  2. That's a good question, and I'm not confident that the research community has come to a definitive conclusion. Part of the difficulty in finding an "optimal" dose is that vitamin K has many forms, and while they all have similar pharmacological activity, they have differing pharmcokinetic profiles.

    What I mean by this is that -- using two forms of vitamin K2 as an example -- MK-7 stays in the body much longer than MK-4. So while both are beneficial to the bones and arteries, you typically need significantly higher doses of MK-4.

    Having said this, I can comment on MK-7 specifically, but only in regards to uncarboxylated osteocalcin vs. osteocalcin ratio (as discussed in a later post on K deficiency in IBD).

    The amount of uncarboxylated osteocalcin (ucOC) to osteocalcin (OC) is a measure of vitamin K status, and in a dose-finding clinical trial looking at MK-7, it was found that only 45 micrograms (mcg) daily was able to activate osteocalcin to a "significant" degree. In other words, 45 mcg of MK-7 lowered the levels of ucOC by 40%, and this level of decrease in ucOC was deemed to reduce the risk of bone fractures significantly. (I'm not sure where this 40% cut-off came from, and they didn't look at MGP, the vitamin K-dependant protein in the arteries.)

    In the same study, it looked like a dose of 120 to 180 mcg/day of MK-7 may be optimal. I think we need more studies to really sort out the optimal dose in relation to clinical outcomes (not just blood markers), but this will likely takes many, many years.

    Hope this somewhat answers your question.

  3. Your information is very helpful. Thanks very much for you response!

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