The following is a transcription of Dr. Cedric Garland's February 19th, 2013 webinar on how Serum Vitamin D Deficiency Increases the Risk of Premenopausal Breast Cancer. To view the visuals and slides, click here. The two windows can be minimized and placed side by side for concurrent viewing.
Vitamin D & Premenopausal Breast Cancer – Deficiency Increases Risk
GRH: Welcome to another webinar by GrassrootsHealth “Scientists Answer Your Questions.” I'm pleased to announce Dr. Cedric Garland who will be addressing the topic “Serum Vitamin D Deficiency Increases the Risk of Premenopausal Breast Cancer.” And here we go with Dr. Garland!
Dr. Garland: Hi!
GRH: Hello! We've got some great slides by Dr. Garland, after which we will go ahead and answer questions. So Dr. Garland, go ahead and take over.
Dr. Garland: Ok! Well, thank you for inviting me to do this webinar. It’s such a pleasure. I feel like I'm very close to a number of you. Some of you are probably quite far away in different time zones, you may be in the middle of storms or the middle of the night but we're able to meet together in this way.
This presentation is largely data assembled, collected, and analyzed by Sharif Mohr. This was Sharif's effort; we’ll see mainly 2 papers that represented a part of 4 papers that Sharif wrote for his doctoral dissertation from University California, San Diego and San Diego State University, recently. Let’s go to the next slide.
Now we'll be talking about how serum vitamin D reduces the incidence of breast cancer but I wanted all of you to see how this got started. It happened when the war on cancer was launched back in the 1970's. The National Cancer Institute was asked by the Congress to make maps of cancer in the United States using mortality. And when we saw this map, my brother Frank Garland and I, who worked at Johns Hopkins at the time, we were stunned by the number of blue areas, which are the really low areas for breast cancer, in the southern tier of the United States. This is almost all of New Mexico, much of Arizona, much of Texas, and the startlingly high rates in the North Eastern quadrant of the United States, and to a smaller degree the North Western quadrant. Because we knew that there was a lot more sunlight in the southern tier of the US than there is in the northern tier and a lot more… a lot LESS sunlight in the Northeastern tier than the north western tier, it fit the expectation that we had exactly. We had been working on another tumor [cancer type] and this one seemed to match it quite closely. So this led to us writing a lot of papers about Vitamin D and how it can prevent breast cancer but ultimately those got tested. Next slide please.
And I'm happy to say that one of the first places that it was tested actually was in the United Kingdom and this was a test of the theory done by Lowe and her colleagues in Fulsom’s Laboratory in London and what they did was they got blood from people who had breast cancer, and from controls, and they found that, as you can see from this graph, there was a 50% lower risk of breast cancer in women with 48 ng/ml of Vitamin D in their serum. This would be 125 nanomoles for those you in Canada or Europe. You can see that there's a pretty good dose reliant response relationship; in fact the R-squared shown at the upper right was 90% which means that 90% of the breast cancer in London in this study was accounted for by Vitamin D itself. That probably applies more generally to the London population. The other key point I wanted to show you besides the downward dose response relationship is how low it goes. If you look at about 60, maybe 62, 63 ng/ml you'll see that risk is down around point two (0.2) or so, so that means that they observed an 80% reduction in the risk of breast cancer with about 63 ng/ml. Next slide please.
So as time passed, more and more people got aboard and started to do studies to try to find out if it was true – that it was really Vitamin D that was making the rates of breast cancer lower in the southern tier of the US, and we did a meta-analysis where we put 2 studies together and we found that when 2 studies were combined it was still approximately 48 ng with a 50% reduction in breast cancer. And as time went on more and more studies happened, and here Sharif reviewed a whole slew of these studies recently, and we find that that number just does not change. And it may be a property of strong biological relationships that, while you occasionally see an exception, overall you just keep getting the same number. Next slide, please.
You can get the full paper and read it yourself, but this is the latest meta-analysis we have by Mohr et al. on Anticancer Research and after all these years it’s still about the same. It’s projected at 47 ng/ml related to a nearly 50% decrease, 45 ng/ml related to a 50% decrease in the risk of breast cancer. It goes from 45 to 48 to 50 ng/ml across numerous studies, (Next slide please), needed to prevent half of the cancer of the breast.
Studies typically have not been divided up in pre menopausal and post menopausal but we had the good fortune to really focus on pre menopausal breast cancers in the present study. By now I would say its been established that vitamin D prevents post menopausal breast cancer, specifically 80% of post menopausal breast cancer but there's still been some questions to whether it prevents pre menopausal breast cancer. Abbas et al. in Heidelberg did this wonderful study that said that yes it does but it also needs replication and it was a case control study so we decided to do a cohort study. Fortunately we had access to blood collected over the past decade or so from women in the Department of Defense, in active duty women in the Department of Defense. And what we found was, that we located 600 consecutive cases of breast cancer and 600 controls who were matched to them on the date the serum was drawn, within a matter of a few days, and this just shows the basic facts of the cases. Now let’s just go to the next slide where we can look at the results.
And at first we were a little disappointed. We thought, “well, it’s nice that the curve is downward but we'd like to see it more downward.” But when you stop to think about it, it is a 40% reduction in pre menopausal breast cancer in women at 50 ng compared to women down at, less than 19, 0-19 ng. And this is pre-menopausal breast cancer which people have, weren't as sure about as they were about post-menopausal. Next slide.
But things looked up in terms of the clarity of the relationship when the investigators learned of the analysis to women whose breast cancer was diagnosed within 90 days of the date that their serum was collected. There was about 125 of these, and what you see here is as the serum 25(OH)D went up, the risk of breast cancer went down. It was, so maybe 2.25 times greater risk at the high end of the scale than at the low end and that means that, well, it’s a reduction by 55% in breast cancer risk. And what stunned us was the dose response relationship and you only see this line with points so tightly along it when there's a mechanism that’s almost exclusively due to the factor. So this convinced us that Vitamin D works very well at preventing pre menopausal breast cancer. But it does it on a very short period of time. Next slide please.
And this is for the non-white women. As we went through the data we were quite shocked to find that it was more dramatic even for the non-white women, that non-white women who were down around 0-19 ng/ml had more than 5 times the risk of breast cancer during the next 90 days as people who were around 50 ng/ml. So if you happen to be non-white, this really applies extremely, so much so to you it's an 80% difference in your risk of getting breast cancer if you're below 50 ng/ml. Next slide please.
So how did this relate to theories? Well, the old theory, going back to 1902, was that breast cancer was due to the mutations. Next slide please.
We don't actually any longer believe this is true and I'll tell you a little more about that. I will share this in the mean time though - this is a study done in Canada which showed that women who had greater than 30 ng/ml of 25(OH)D in their blood, they had a relative risk of 0.58 meaning that they had remarkably less, 42% less chance of dying with breast cancer than women who had less than 20 ng/ml. Next slide please.
So we developed a theory that breast cancer does not start with any genetic event but rather simply with the loss of tight junctions. And these are junctions that hold the cells together, make them adhere tightly to one another and they send signals saying not to grow and they also can share nutrients through the junctional systems. We believe that cancer involves these steps starting with D for Disjunction which is the most important one and the one that the Vitamin D influences dramatically and then Initiation - much less important, Natural Selection - very important, Overgrowth is just what happens as a result of Natural Selection and the last 3.stages are probably going to disappear once we get Vitamin D levels high enough. Next slide please.
So that's DINOMIT and these are the little structures that hold the cells together. There are many kinds of them but what they have in common is they are all produced in response to Vitamin D which enables synthesis of structures and proteins at 2500 points on the human genome. Next slide please.
And the way it works is that cells are held together by hinges that look almost like a railroad and there’s a, it takes 2 things – it takes cadherin, a compound regulated by Vitamin D, and calcium, that help the cells stick together. Without either one, they don't stick together. Next.
And once that intercellular adherence is lost the cells begin to grow. They compete with each other. Those that reproduce fastest and are most aggressive become greatly over-represented in the compartment, the cellular compartment known as the terminal ductal globular unit in the breast, and they begin to eat away at the membrane surrounding that unit and ultimately one breaks through followed by others. Next slide please. And that's the definition of cancer, when those cells violate that membrane - penetrate through it. Next slide please.
But then later on as the tumor is growing, here the tumor is shown as a grey mass, it reaches a point where it can't grow anymore and will die if it cannot recruit blood vessels. But when it reaches that point in someone whose Vitamin D is very low, we see a release of a compound called VEG-F, Vascular Endothelial Growth Factor - F, that causes blood vessels to grow into it. And so if you can imagine little particles of VEG-F being secreted by the tumor and then little arterials growing up from that capillary and that process is also under the control of vitamin D. If the Vitamin D levels is high, the little capillaries don't connect to the tumor; the tumor eventually exhaust itself through autophage, the cells actually dissolve each other and it turns into a small scar and that's all that's left of the breast cancer if it can't recruit blood. Next slide please.
So that's the mechanism and after all these years since, actually this began in the 90's with the first realization that we know of, of the relationship between sunlight, Vitamin D and breast cancer, with the same finding as Lowe et al. had at the very beginning. Namely, if you can get serum 25 (OH)D up to 48 ng, you can cut the risk by half and we believe that if you can get it up to 65 or so ng that you'll reduce it by at least 80%. Next slide please.
Science tends to repeat things again and again it would seem, but a good target for preventing breast cancer right now is 50 ng/ml. As time goes on we're probably going to see this increase, but we always want the best balance between efficacy and knowledge of what adverse effects might be. And so if you're in a sunny climate in the world and you're fair skinned, your Vitamin D levels can get quite high. Anywhere from 54, usually up to about 70 but occasionally 90 ng/ml and so those are safe; and we excrete 3,000-5,000 IU's a day of Vitamin D so any amount of Vitamin D consumed at or below that level is going to be safe too. Next slide please.
So what we'll do here quickly is more or less summarize for you the things that should be done to prevent breast cancer and, if you have it, what should be done. Next slide please.
So you need Vitamin D3. Next
and we're aiming for 40-60, preferably at least 50. … If you're in Europe or Canada these are the values for you [100-150 nmol/L, preferably 125 nmol/L]. Next slide please.
And oral intake is best determined by testing the blood and then giving the oral intake needed to maintain that level but its going to be at least 4,000 IU/day. Next slide please.
And whenever you are taking a lot of Vitamin D its good to take calcium with it, 1,000 mg or more if you and your doctor decide it’s needed to maintain bone density, and keep up the fluid intake in order to prevent kidney stones although I think the risk is very minimal if at all. Next slide.
And if you have already breast cancer, or you have a patient with it, test their blood for serum 25(OH)D and if you are a physician you may want to order calcium and ionized calcium. Next slide please.
And start patients with breast cancer on 4,000 IU/day and calcium, the Vitamin D and calcium, regardless of what else you are doing unless the patient is hypercalcemic. Next slide please.
And then Titrate of Vitamin D3 intake, incidentally it must be Vitamin D3, you are more or less wasting your time if its Vitamin D2, titrates to maintain 50-60 ng/ml at all times. This means especially during the winter but it should be all year long. Next slide please.
And you should retest the patients monthly for the first months to make sure they are off to a good start and then every 6 months or so thereafter. Next slide please.
It should as an essential part of breast cancer management as chemotherapy or radiation. And for some patients, particularly those who are not extremely fair skinned, you could suggest that they spend 10 minutes a day outdoors near solar noon with 40% of skin exposed. The skin exposure is very important part of this equation. And with no sunscreen for the first 10 minutes or so. You want to always stay under the dose to cause the skin to turn pink. Next slide please.
And so we're back where we started with the geography that led us down a long road, over a period of now 30 years or so, to where we are today and I can tell you with complete confidence we are somewhere where we can prevent 80% of breast cancer if we can just get people’s Vitamin D levels up all year long all around the world to levels needed to prevent, both pre- and post- menopausal breast cancer.
Thank you for listening and I'm ready for any questions.
GRH: Ok, thank you so much! That was a great presentation, Dr. Garland. And I am going to switch to our question slide. Ok great! So the first question: What is 25D doing to the a) normal cells to prevent breast cancers from forming, and b) to the cancerous cells to stop their growth?
Dr. Garland: Well, you’d think it would be a long and complicated answer but its really, like so much of nature, very short. It’s making the cells stick together. When they stick together they don't compete. When they don't compete, there's no natural selection. With no natural selection, there's no evolution and with no evolution there's no cancer. That applies to normal cells and even to cancerous cells that still have Vitamin D receptors. Vitamin D receptors are very robust so most cancer cells still have it and it stops their growth by causing them to stick together. When they stick together they inhibit each others growth. Its actually the first phenomenon discovered in carcinogenesis was that the adherence of one cell to another inhibits the growth of its neighbor and its playing out after 100 years through Vitamin D.
GRH: What about deficiency and menopausal and post menopausal breast cancer? I know you briefly touched on that but could you expand a little more?
Dr. Garland: Sure, Vitamin D deficiency produces breast cancer during the pre menopause, during the menopause and in the post menopausal period. It’s just that the effect is much more rapid and immediate in the pre menopausal period because the breast is being constantly stimulated by estrogen and progesterone in each menstrual cycle and the growth is very fast. The growth is so fast even that under the age of 50 we, generally speaking, can not catch it with a mammogram that's why mammograms are so ineffective. The effect is just the same. Overall it will be a 50% reduction with 48 ng/ml and potentially 80% reduction with higher 25(OH)D its just that that plays out over a longer time span in the post menopausal than it does in the pre menopausal period.
GRH: What serum level of 25D is required to adequately reduce the risk of breast cancer?
Dr. Garland: Well, right now its 50%, eliminates 50% of breast cancer. 50 ng/ml eliminates 50% of breast cancer. If we went up to say 65, the relationship is so linear that I believe that that would eliminate 65% of breast cancer. At some point we'll be recommending that women go up to approximately 80 ng/ml in order to reduce 80% breast cancer, but the risk and benefits are still being balanced. Right now it doesn't look like there's higher risk if there's higher values but we like to have consensus among the scientists, so right now we are saying "lets get rid of at least half" which would require at least 50 ng/ml.
GRH: Are there different recommendations for women with breast cancer in their family history or is it the same for all women?
Dr. Garland: It appears to be the same for all women, but it is extremely urgent in the pre menopausal period because even short delays in starting Vitamin D can be a period during which a tumor can evolve. It’s a far more acute disease in the pre menopausal period. So if someone has a family history of pre menopausal breast cancer they, more than anyone, need to be starting Vitamin D immediately. But it really does apply probably equally to all women.
GRH: Should I stop taking prescription Vitamin D tablets if I have very dense breast tissue and have had an aunt who had breast cancer?
Dr. Garland: Well, to begin with, you probably should not be taking prescription Vitamin D tablets because, at least in the US, almost all prescription Vitamin D tablets are not Vitamin D3. For some reason they're Vitamin D2. Related to how the business works, so yes, I would stop taking prescription Vitamin D2, if that's what it is, and take prescription, or non-prescription, Vitamin D3 tablets. And you should not stop because the breast tissue is dense. If anything that would be more of a reason to be taking Vitamin D or not stop because of having a family history. Both are all the more reason to do it.
GRH: Do we have any good data on Vitamin D levels during treatment for breast cancer? Do we have any level that seems appropriate for women to take during chemotherapy? We have limited our patients to 2,000 IU/day during treatment.
Dr. Garland: We sorely need that data. We don't. All we know is that women who have high Vitamin D at baseline are 40% or so more likely to survive during the next decade or so but we don't have serial measurements, unfortunately. But most people, I think, would suggest at this point 4,000 IU/day for everyone aged 9 or older, male or female, during chemotherapy or not.
GRH: How do Vitamin D, estrogen and progesterone work together to reduce pre menopausal breast cancer?
Dr. Garland: Estrogen and progesterone pulses during the menstrual cycle are driving the evolution of pre menopausal breast cancer. Vitamin D stops that evolution.
GRH: What range do you think Vitamin D levels should be maintained at for breast cancer survivors?
Dr. Garland: Well, I would say no less than 60 ng/ml but it should be scrupulously tested so they don't get periods where it dips down below 20 ng/ml which can happen after a long winter, or time spent inside.
GRH: I have had breast cancer twice in the past 6 years, both were caught early and removed by lumpectomy. Besides increasing my Vitamin D levels as a participant in the D*Action study, what are the most effective natural ways to prevent another occurrence?
Dr. Garland: Well, its just exercise. Once again, exercise, preferably on a regular basis outdoors, and avoid drinking a lot of alcohol. No more than one or maybe one and a half drinks per day.
GRH: What are the optimum Vitamin D3 levels to avoid breast cancer? What if you have early stage breast cancer? Can you slow or stop it by supplementing with Vitamin D3? If so, how much should you take? And you may have already addressed this question….
Dr. Garland: Yes, well just to reiterate a little bit, we're looking for 60 ng/ml, in anybody who has breast cancer, in the serum. That's going to be consistent with taking somewhere in the range of 4,000-6,000 International Units per day of Vitamin D but it should be tested. Can you slow or stop it? Yes, the data from Canada suggests that having a high Vitamin D is slowing the growth of breast cancer so the answer would be yes.
GRH: And Dr. Garland I had a very interesting question come in. What about men? Recently I have seen an increase in male cancers.
Dr. Garland: It appears to be a completely different epidemiology in men. And it’s sort of a conundrum. It’s far rarer in men so it hasn't received nearly as much attention, but we have no evidence to date that any of what we're talking about for female breast cancer is applicable to men. Whatever is causing it in men seems to be a totally different pathogenesis.
GRH: Hmm, interesting. It looks like we have time for one more question, if you don't mind Dr. Garland.
Dr. Garland: Sure!
GRH: My daughter started menstruating at age 10. At what age should women start taking Vitamin D?
Dr. Garland: They should take it in infancy, starting with the TULI [Tolerable Upper Level of Intake] of the US National Academy of Sciences which is one 1000 IU/day the moment the girl is born and then increasing at the end of the first year to at least 1500 IU/day and then slowly increasing with each year of growth to a total of 4,000 IU at age 9. And it’s very important for girls to get Vitamin D and ideally for them to get it beginning at birth.
GRH: Ok great. Well, we are approaching our time limit and sorry, and I just wanted to thank everybody for attending today. Please tune in next Tuesday at 10 am PST to listen in on Dr. Susan Whiting who will be discussing “Vitamin D levels are declining, however MS, cancer, diabetes and more on the rise. How can you protect yourself?” And you can register through our website at grassrootshealth.net/webinars. And I want to thank you again, Dr. Garland, for your time and your information, and thank everybody for listening in!
Dr. Garland: It was a pleasure, Jen! Thanks to each of the listeners, and people who submitted questions, for allowing me to come in to your offices or your homes and chat with you about this. It was a great pleasure for me.
GRH: Of course. And thanks to all the listeners from GrassrootsHealth and please be sure to visit our website grassrootshealth.net where you can order your Vitamin D test kit and in doing so you will join our D*Action program. Thanks again for listening in.
Additional Q&A with Dr. Garland on Premenopausal Breast Cancer
GRH: Welcome back to an additional question and answer session with Dr. Cedric Garland, who has been speaking on the topic of Serum Vitamin D Deficiency Increases the Risk of Pre-menopausal Breast Cancer. And Dr. Garland, welcome back!
Dr. Garland: Thank you, Jen!
GRH: So, a few more questions that we didn't have a chance to answer before and I'll just go ahead and jump into them right now.
Do we know if Vitamin D can prevent or inhibit the 10 forms of genotypic breast cancer? (and there's a notation for Caldas et al.) Have there been any studies on Vitamin D on its effect on triple negative breast cancer?
Dr. Garland: We have every reason to believe that Vitamin D works on almost all forms of breast cancer, with the exception of the kinds that are secondary to inflammation of the… coming through nipple. In some parts of the world where breast hygiene is not as good as it is in say the US or Canada or Europe, then we do see occasional cases… or China and the Asian Peninsula, we do see cases where there is an infection of the breast, a mastitis, that occurs coming up through the nipple and that does not appear to be controllable by Vitamin D. But, within the United States and most of the West, and much of China and the Asian Peninsula, the breast cancers are not inflammatory, 99% are not inflammatory. So, as far as we can tell from the epidemiology that we have, of course we need more, it is not appear that there are other cancers that are not subject to the influence of Vitamin D. It seems to be inflammatory breast cancer that's most, with the exception to the rule of that 1% or so tumors. As far as triple negatives, there is some work on triple negative breast cancer and namely laboratory work, but it looks like Vitamin D works, does its magic very well in triple negative breast cancer, which is important because we don't have many other options in people who are triple negative.
GRH: Blood levels desired for prevention in general and especially for those at increased risk, for example have family history/are BRCA positive. I'd like to hear about this in the context of both pre menopausal and menopausal women.
Dr. Garland: Both pre menopausal and post menopausal women need to maintain Vitamin D in the range of 40-60 ng/ml. If there are specific risk factors, such as a family history or a genetic predisposition, the general idea would be to work with the high end of that range - around 60 ng/ml. Because these individuals are at higher risk in the risk/benefit equation its quite suitable around 60 ng/ml. Maybe someday we'll be asking them to aim higher but right now in terms of the consensus among Vitamin D scientists and physicians, I think that right now we want to aim for 60 ng/ml in anyone who's either at high risk of breast cancer or who has breast cancer.
GRH: Have you had other participants who have had poor gut absorption possibly due to Radiation Overdose & subsequent GI surgery to remove part of the small intestine & large intestine? What do you do about absorption then?
Dr. Garland: In questions… In patients in which there's a question of absorption the key is testing. The testing of the levels of serum 25(OH)D. It may take much larger doses than we're using in ordinary healthy individuals to get through that barrier. Inevitably, there will be some absorption but it will take possibly many times the standard dose. The only way to do that in a systematic way is to measure the serum 25(OH)D, to titrate the Vitamin D levels upward until they get in the range of 40-60 ng/ml and then use that level, whatever it happens to be, because that's the effective level of Vitamin D on the tissues and there's no way to know (excuse me) exactly what that level is. But with testing, there's… it’s not at all difficult to maintain high levels although it may take very high Vitamin D3 input.
GRH: Ok. And several questions came in regarding sunlight vs. supplements. What do feel is the best way to get Vitamin D: through supplements, or through sunlight exposure, or a combination of both? And what about people who live at the northern latitudes during the winter? What are your thoughts on that, Dr. Garland?
Dr. Garland: I think a lot of the strategy is to take a combination of both. It’s an old lesson in epidemiology that you try to keep closest as possible to the original exposures that produced the benefits. And our research began with the effect of solar radiation of sunlight, and it’s very reproducible so it’s, I think, very important to include it in the program of prevention and treatment of breast cancer, some exposure's desired. Of course, we don't want to make it too much, but for most people 10, for some 20, minutes a day is sufficient. We want it at a point below where the skin turns pink as a consequence of the exposure. Most importantly, a neglected part of this, actually there are two, is that it's only worthwhile to do it during the period around solar noon, which is within an hour - an hour before to an hour after the point where the sun is highest in the sky and that's usually noon except for areas where there's Daylight Savings time and then the period of solar max is at 1:00 o’clock, or solar noon. So it has to be pretty much between 11 and 1, except during the Daylight Savings time period when its between 12 and 2, and probably the most neglected factor of all is that at least 40% of the skin has to be exposed in order to produce enough Vitamin D with that duration of exposure. It can't be solved with longer duration because there's only so much precursor Vitamin D in the skin and there are diminishing returns with longer duration but there's no diminishing return with increased skin area. So that means with most people, wearing, for men, shorts and for women maybe shorts and a top but having the shoulders completely exposed, ideally as much as possible the back and abdomen exposed. It’s often, most people find that for them to do that while they're exercising it gives them sort of an excuse to be out in the sun so attired. But yes, it should be a combination. You’ve got to cover all bets. The only exception is the people who are very fair skinned, for whom doctors have told them that they are at high risk for skin cancer in which case solely supplementation may be the best answer combined with testing to make sure they are getting enough from oral supplementation. That testing should be done each year preferably in February or March when the levels are lowest because it’s that time that the low levels allow the cancer to evolve.
GRH: Ok, great! Well, thank you for answering those additional questions and we had a little animated video during our PowerPoint presentation from our first webinar that would not play so I would like to know, Dr. Garland, how does Vitamin D prevent breast cancer? How does it work?
Dr. Garland: Well, in the pre-menopausal breast cancer it’s working mainly by inhibiting the process that you’re seeing in the animation. Let’s show that animation again. Normally the tumor is like a big blob that sends out endothelial growth factors, these cause blood vessels to grow into and supply the tumor with blood and that’s the part in which the tumor becomes bigger and starts spreading to other parts of the body. And this is a point which is not typically detectable mammographically so it’s really important to catch it as the new growth detections often fail - generally fail if this isn’t blocked. What we're dealing with - we're seeing the little green dots, that's vascular endothelial growth factor being secreted by the tumor, something that they all have the ability to do and the blood vessels growing in to it. Vitamin D blocks those little green dots, that vascular endothelial growth factor, its receptors are blocked, apparently by Vitamin D, and there is a lot of laboratory work now showing that Vitamin D prevents this profusion of the tumor blood and if it doesn't get the blood the cells turn on one another, they burn themselves out, it comes to a crash & will ultimately scar and no breast cancer occurs. It’s very important in the pre menopausal period that people prevent this process. During post menopausal period this is probably part of it too. That it, Vitamin D also prevents evolution in tumors all along its natural history and that’s the two ways that Vitamin D prevents breast cancer in the pre and post menopausal years.
GRH: Very interesting. Ok well, I believe that's it, Dr. Garland. Did you want to cover anything else? Did we cover it all?
Dr. Garland: I think you covered it all!
GRH: Thanks again for doing this webinar and I look forward to having you again soon!