Below is a transcript from Todd Whitthorne’s interview with Dr. Robert Heaney, professor in the Department of Medicine at Creighton University in Omaha. Dr. Heaney has spent over 50 years in the study of osteoporosis, vitamin D, and calcium physiology; he’s authored three books and has published over 400 scientific papers, so when it comes to the world of vitamin D, and calcium in particular, Dr. Heaney is one of the leading gurus, literally, in the world! Click here to listen to the interview
This is Todd Whitthorne and I’m very pleased today to be joined once again by Dr. Robert Heaney, who is a professor in the Department of Medicine at Creighton University in Omaha. Dr. Heaney has spent over 50 years in the study of osteoporosis, vitamin D, and calcium physiology; he’s authored three books and has published over 400 scientific papers, so when it comes to the world of vitamin D, and calcium in particular, Dr. Heaney is one of the leading gurus, literally, in the world! So Dr. Heaney thanks again for joining us.
It’s certainly a pet peeve of mine, and I know it is one of yours as well, and that’s primarily the media – how they love to focus on harm, or potential harm, as opposed to the overwhelming benefits of certain topics, and what I’m primarily referencing is the of the recent headlines from the US Preventive Services Task Force saying that postmenopausal women should avoid taking low daily doses of vitamin D and calcium to ward off bone fractures. They say that those amounts have no benefit for the primary prevention of fractures, but there is evidence that taking them could increase the likelihood of kidney stones. I know they released this last summer, and then it suddenly got another whole round of headlines, and I’m getting calls and e-mails with all sorts of questions about it and it drives me a little bit nuts! What about you?
Well, yes, it was originally published in draft form in June of last year and that elicited a lot of media reaction because as you correctly point out the media love controversy, and if this seems to contradict the accepted wisdom then that’s considered newsworthy. However, it tends to get exaggerated. The current recommendations, which are essentially the same as the draft form nine months ago. The current recommendations are really quite confusing because they do recommend taking calcium and vitamin D for the prevention of falls in the elderly, but they don’t recommend it for the prevention of fractures. Well, so what’s a person to do? Well obviously what the person should do is continue to take calcium and vitamin D supplements.
What they mean when they say they don’t recommend is not saying you shouldn’t do this, it’s saying we don’t have the evidence to permit us to recommend this to you, and the kind of hidden subtext is “well it could be helpful, but we just don’t know.” Now in fact a lot of experts in the field feel they do know as a matter of fact…
I was going to say! What they know is not what you know, is it?
Exactly, or right! And it’s worth pointing out that the Preventive Services Task Force consists of public health people, not one of whom, to my knowledge, and I recall I checked his last June, not one of them has ever published a scientific paper on calcium or vitamin D. I mean, they’re given a task, and the task is apply a certain set of rules to a set of published papers, and see if that constitutes evidence to make a formal recommendation, and if it doesn’t meet the standards of those rules, then they say “well, we can’t recommend.” But it’s very important that they’re not recommending against something, they’re simply saying they can’t recommend “for” it and there’s a big difference.
I understand. From a controversy standpoint, going back looking at PSA (Prostate-Specific Antigen Test) or mammograms, it’s not the first time that the US Preventive Services Task Force seems to be in conflict with a lot of the research world. But let me ask you in general, can calcium and vitamin D supplements increase the risk of kidney stones? What are your thoughts?
No. No. No. I’m glad you asked that question. The truth is exactly the opposite. It’s been shown in good experimental studies, that increasing calcium intake decreases the risk of kidney stones. Now, I’m sure many people find it counterintuitive because kidney stones are made from calcium, and I must have too much calcium in my body and so I should cut down my calcium intake. Well, it’s been shown that if you do this you’ll double your risk of getting a recurrence of the kidney stone. There was a wonderful study from Italy published eight to ten years ago now published in the New England Journal of Medicine describing the results of precisely such a study, and they had a set of male kidney stone formers and half of them were put on a low calcium diet, and the other half were asked to increase their intake of calcium, cheese and stuff you know, and those who increased their intake had half the recurrences of those who restricted their intake, and that fits the biology. The reason for that, as we may have discussed previously Todd, is that one of the principal risk factors for kidney stones is a chemical compound called oxalic acid or oxalate, the salt form of oxalic acid, and some of that comes into us into our body through our diet, through food. Well, oxalate is a very potent stone former, it’s a more important stone former than calcium, and if you have a high calcium intake by mouth, much of that calcium stays in your intestinal tract and combines with oxalate in food and prevents the oxalate from being absorbed into your body, and therefore doesn’t have to be excreted to the kidney…, and therefore it’s not in the urine to predispose to kidney stone formation.
There’s very good biology behind this, and lots of experimental data, and it does seem kind of counterintuitive, and many doctors don’t know what to tell you to do if you have kidney stones, so they say well you better cut out your milk or dairy or calcium supplements, or whatever the source may be. But that’s actually bad advice, and we have to try to counter that, so no, it does not cause kidney stones.
The reference there is a single paper that came out of the Women’s Health Initiative in which in the group receiving calcium and vitamin D supplements there was a seventeen percent increase in risk of kidney stones. Seventeen percent – not very big. But in fact if you look at the other segments of the Women’s Health Initiative Study, they had exactly the same kidney stone risk as this group that got the calcium and vitamin D supplements. So there really is no strong evidence there, and all the other evidence is in the other direction. It’s also worth noting that the vitamin D dose prescribed in the Women’s Health Initiative was only 400 IU (international units ) per day, and it’s worth noting that the compliance with the medication in the Women’s Health Initiative is only fifty percent.
So that means on average, these people were getting only 200 IU (international units) of vitamin D - that’s not capable of doing anything, good or bad! That’s such a tiny dose, that it couldn’t possibly make any difference. But that’s the only evidence they had to go on. The point is that it was a big government study, and the US Public Services Task Force has these strong government connections so one talks to the other and they kind of feed off of one another. But the data points in exactly the opposite direction.
Well that’s very helpful, and you’re very clear in allowing us to understand exactly how that happens. One other headline Dr. Heaney, that I want to mention, and I’m sure many people have asked you about is the risk of calcium supplementation in terms of increasing the risk of heart attacks. What are your thoughts on that?
Well, thank goodness that you don’t have to rely on my thoughts – that’s been clearly refuted in papers and major scientific journals in the last six months to twelve months, but mostly since last fall, and there’s always lag time because when those things came out, this was a group of New Zealand investigators who had seemingly found this kind of an effect in the study they did, and they’ve gone around the world with kind of an evangelistic fervor to tell people to be careful this could be making them worse by giving them heart attack. Well is a total re-analysis of big studies like the Women’s Health Initiative in this case, again, shows that this simply wasn’t true. It’s not just that it wasn’t found in the Women’s Health Initiative, but the New Zealand investigators had gone into the NIH database and had kind of cherry picked or preferentially selected some of the cases from the Women’s Health Initiative and used that to support their thesis. So, it was very important, therefore, that the people who had access to, and in a sense control of, the entirety of the data of the Women’s Health Initiative, repeat their analysis and they did, and they published that last fall and the answer is there’s nothing there.
That’s great news.
So, the problem is that if you eat if you stopped taking calcium because of fear of a heart attack then the chances are you’ve increased your risk of a hip factor, and so more harm has been done. And I think it’s very important to say we all need more calcium and we all need more vitamin D and there are some ways to get that, but you mustn’t worry about an increased risk of heart attack because the evidence shows it’s not there. It’s not just that there isn’t any evidence to show it is there, it’s actually the opposite, it’s not there at all – there is no reason to believe that.
One more question Dr. Heaney. I know you’ve spent a great deal of your life studying these topics. The recommendations now seem to be at least 2000 IU of vitamin D per day is a pretty good starting point for most people. I know you have commented and lectured frequently about the dosage of 2600 IU reduce risk of falls and fractures, as well as other medical issues, but still, there is a huge variability between a three and six fold variance in terms of how we as individuals react to vitamin D. So what are your recommendations for both vitamin D and calcium for men and women?
Well, I tend to swim against the stream a little bit here, and in this connection I should alert you to the fact that the US Preventive Services Task Force is once again looking at this vitamin D issue and raising the question of whether we should screen for vitamin D deficiency, and I’m quite sure that they’re going to come up with a “No, we shouldn’t.” I know the American Society of Clinical Pathologist, in trying to be good citizens, but I think bending over backwards, have identified five tests that physicians should think twice about ordering because, they, in their judgment, are probably not very helpful, and one of them is measuring vitamin D status…, and I think that’s wrong. But that’s all kind of preamble to the answer to your question. The only way to tell whether you’re getting enough vitamin D is by measuring. You have to measure what’s in the blood, because as you pointed out, the response to a given dose varies over six-fold range. We think that that’s because we think that that’s because different people have different capacities of the enzyme, probably mostly in their livers, that is responsible for converting vitamin D into the form that we measure in the blood stream, that is 25-hydroxyvitamin D. Some people are what I call very slow hydroxylaters, and others are every fast hydroxylaters, which means they have a lot of the enzyme necessary to do it, and in the other case means they don’t have much of the enzyme, so they don’t get as much for their vitamin D dose as somebody else does, and that means they need twice as much, or three times as much, or maybe even six times as much as the other person. We can’t tell that from looking at their forehead – there isn’t any UV or invisible ink on the backs of their hand you can scan with a UV lamp and see whether this person will need more or less. A good place to start, as you say, is at 2000 IU (international unit) per day, and once you’ve done that we like to measure them three to six months later. If they’re up in a good range, we stick with 2000 (IU); if they’re not then we double it until we get them where we want them. But you can’t tell that without measuring, so I’m strongly in favor measuring.
Okay. How about (recommendations) for calcium? Is there a difference between men and women? I know calcium is more challenging because there’s not a blood test for calcium like there is for vitamin D.
There’s no way to assess calcium by a simple test. Vitamin D is really a wonderful nutrient in that regard as it permits measurement the status, and of the compound that the body is actually looking at and needs and uses. But we don’t have that for calcium as you correctly point out. Actually, this is a bit of a digression, but in all of these nutrient controversial areas, I take as my benchmark ancestral intake; that is, what did humans take before the agricultural revolution, surely before the Industrial Revolution, but before the agricultural revolution which was a giant change in the kinds of foods we ate. The natural vitamin D level under ancestral conditions would’ve been between 40 and 60 ng/ml. We know that because it is been measured in East African tribes that are following ancestral lifestyle, so I take as my benchmark, well I’m back in my blood level up to where it would have been had I been living under the more primitive circumstances.
And the reason for that is that our physiology has been fine tuned to what the environment provided during the millions of years in which the human body was developing, and human physiology was evolving. Different animals have different requirements everything. For example, rats and mice are primarily nocturnal animals and therefore don’t get vitamin D from the sun in usual way. They have very low requirements and they metabolize vitamin D very differently. But we grew up in equatorial East Africa that’s how we developed, so we were getting sun every day of the year, and of course we didn’t wear clothing and didn’t have a lot of fur, so we got a lot of vitamin D. Now when it comes to calcium, the best guess is that we probably were getting from 1500 to 2500 mg of calcium per day, and again, I’d like to take that as my benchmark. Now that doesn’t have to come in, in the form of supplements, it’s probably better if it’s taken in as food, but the important thing is to get it in. The reason that it’s better as food is that with the decreased physical activity of the modern urbanized human, we can’t consume as much food as we did before, and many of the foods available to us are calcium poor, and micronutrient poor, and if we provide just the calcium in the form of the supplements then we’re not taking care of the other micronutrients that are probably deficient in the same individuals. So, I’m a strong advocate of natural food sources of calcium, but there’s definitely a role for supplements and that’s to be what their name says they are – supplements. But there’s a lot of sense to people take nutrients in and in the sense of taking medicine for a specific endpoint all nutrients are necessary for all body tissues, and it’s a mistake to think of a single end point because what with both calcium and vitamin D, I can name dozens of systems that are adversely affected by inadequate intake of either or both nutrients, so the goal is our bodies need these things, all of our organs, and all of our tissues need these things, and we should be focusing on this as nutrition, and not as medication.
Very Good. Well Dr. Heaney, I want to thank you for your time. I want to point out to our listeners that Dr. Heaney has several wonderful scientific presentations available on YouTube (http://www.youtube.com/). If you like to really dig deep and hear about some of Dr. Heaney’s research, and the things he’s been involvement there are three or four really good presentations available on YouTube. Continued success, and as always, I appreciate your time very much.
Thank you very much.
Dr. Robert Heaney our guest today on our healthy living podcast. As always you can get more information at www.CooperAerobics.com
- Response to Vitamin D: summary chart of 8 studies – March 2013 Dr. Heaney was a co-author
- All items with the word Heaney in VitaminDWiki 726 as of March 2013
- Vitamin D Insufficiency is less than 32 or 40 ng – Heaney 2012
- Low Vitamin D with dark skin, even if live closer to equator and higher altitude – Feb 2013
- Vitamin D level can be high, but little benefit: due to kidney, genes, low Magnesium etc,
- Free vitamin D (VDR) may be more important than total for bladder cancer – March 2013
A high serum level of vitamin D does not mean that there is a high level inside of the cells
- Should people at high risk for vitamin D deficiency wait 5 years -Feb 2013
- Must balance co-factors when increasing vitamin D 500 Ca, 500 Mg - which has the following concept graph
- IoM again fails to look at interactions - Nov 2010
has the graph: dangerous to have too much Calcium while having lots of vitamin D