Are endogenous nutritional supplements better? 4. mayo 2008 William Davis (6) Just a muse. Endogenous substances are those that are already contained within our bodies. They are part of basic human equipment. Exogenous substances are those that come from outside of our bodies. This includes various substances in foods, drugs (most, though not all), and pesticides. I often mull over all of the tools we use in the Track Your Plaque program to achieve control over this thing called coronary plaque. It struck me that just about all the supplements we use that seem to provide outsized benefits are all endogenous substances themselves:--Omega-3 fatty acids from fish oil--Vitamin D--l-arginine--Niacin (vitamin B3)Many of the other substances, though not directly relevant to our plaque-control efforts, but are among the most effective nutritional supplements, also supplement endogenous levels: calcium pyruvate, creatine, acetylcarnitine, DHEA, testosterone, progesterone, growth hormone, pregnenolone, phenylalanine, tyrosine, melatonin, etc. Curiously, most drugs are not meant to directly supplement endogenous levels, but are designed either to enhance or block an enzyme (e.g., acetylcholinesterase inhibitors that block breakdown of acetylcholine; HMG CoA reductase inhibitors to block cholesterol synthesis; angiotensin converting enzyme inhibitors to reduce blood pressure), to exert toxic effects on an organism (antibiotics, antivirals), or to exert an entirely unique effect that does not ordinarily occur in the human body (some anti-cancer drugs, for instance). (This is an admitted, vast over-simplification.)That's not to say that any endogenous substance is desirable or safe when supplemented. Cortisol, thyroid hormone, and estrogens are three examples of endogenous substances that have downsides when administered at slightly more than physiologic concentrations. Nonetheless, it makes me wonder if the world of endogenous substance supplementation has not been fully explored. Are there other endogenous substances that are as potent and wonderful, for instance, as vitamin D but not yet fully appreciated? I'm sure there are.
Vitamin D Newsletter reprinted 1. mayo 2008 William Davis (2) Reprinted here is the unfailingly informative Vitamin D Newsletter from Dr. John Cannell. Although there's little here specifically about heart disease, there's so much great information about vitamin D that I thought most would still appreciate it. The Vitamin D NewsletterMay, 2008Yesterday's Washington Post article, Too-Good-To-Be-True Nutrient?, sums up the April 9th vitamin D symposium at UCSD in San Diego, which was nothing short of spectacular. Carole Baggerly outdid herself organizing it and explaining how she got involved. Make no mistake; Carole is both serious and energetic. She told about her efforts to introduce resolutions at upcoming meetings of various professional groups. Then she introduced the volunteers from the San Diego Black Nurses Association who made sure the conference went off without a hitch. Then Carole introduced the four speakers. The slides of each speaker are available at Grassroots Health. Before I tell you the highlights of the conference, I'd like to tell you about another conference, this one in Germany, this May 17th and 18th. It is the Third International Symposium on Vitamin D Analogs in Cancer Prevention and Therapy. Readers know how I feel about giving analogs to vitamin D deficient patients instead of vitamin D but speakers include Michael Holick, Reinhold Veith, Bill Grant, Tai Chen, Heidi Cross, David Feldman, and Roger Bouillon, all of whom know the importance of the nutrient. Most of this conference is for scientists, not lay people. However, Michael Holick is the first speaker and if you have not heard his latest talk about vitamin D, it might be worth a trip to Germany.The first San Diego speaker was Dr. William Grant. Since leaving NASA to begin a full-time career as a vitamin D researcher, Bill has published dozens of studies and has another dozen in the works. Using ecological studies (from Greek oikos, house + German -logie, study or studying your own house) of UVB irradiance and cancer, Bill reported that 15 cancers (colon, esophageal, gallbladder, gastric, pancreatic, rectal, small intestinal, bladder, kidney, prostate, breast, endometrial, ovarian, Hodgkin's lymphoma, and non-Hodgkin's lymphoma) are associated with lower UVB light. He concluded that 257,000 cancer deaths in 2007 in the USA were accounted for by inadequate vitamin D levels. Of course the problem with ecological studies is that it easy to be vitamin D deficient in Miami, all you have to do is listen to your doctor's advice and stay out of the sun. Recently, a group from the Arizona Cancer Center found almost 80% of Arizonians had levels below 30 ng/ml. So much for sunny spots.Jacobs ET, et al. Vitamin D insufficiency in southern Arizona. Am J Clin Nutr. 2008 Mar;87(3):608-13.The next speaker was Professor Cedric Garland. I found myself wondering how he did it. I became convinced that vitamin D prevents cancer five years ago. Cedric and his brother Frank and his colleague Ed Gorham knew it 30 years ago! I know what it is like to tell someone that vitamin D prevents cancer and see them think, "Here we go again, another miracle vitamin." I know what it is like to try and explain and watch people die unnecessarily. But I've only had that experience for five years. Cedric has dealt with that frustration for thirty years. Almost thirty years ago, Cedric and Frank Garland published evidence that vitamin D prevents cancer. In fact, it was Cedric's first publication. Thankfully, the paper was recently recognized as being so important that it was republished in 2006 by the International Journal of Epidemiology. You can read the entire paper for free by clicking on the second link below and then clicking on "free final text", courtesy of Oxford Journals.Garland CF, Garland FC. Do sunlight and vitamin D reduce the likelihood of colon cancer? Int J Epidemiol. 1980 Sep;9(3):227-31.Garland CF, Garland FC. Do sunlight and vitamin D reduce the likelihood of colon cancer? Int J Epidemiol. 2006 Apr;35(2):217-20. Cedric began by showing the incidence of type-1 diabetes and multiple sclerosis by latitude. I had no idea that the latitudinal data was so strong for type 1 diabetes in children. This disease is almost nonexistent around the equator. Type-1 diabetes is but one of the three modern childhood epidemics caused by the sunlight-hating dermatologists, the other two, I think, are autism and asthma. Next he showed latitude and 25(OH)D levels, which reminded me to be suspicious of high levels, unless they use accurate methods of detecting 25(OH)D. Some methods used, even in this country, are over detecting vitamin D and telling patients their levels are above 50 ng/ml when they are, in reality, much lower. Cedric's data showed Thailand had mean levels of 70 ng/ml, which I doubt and suspect were due to inaccurate 25(OH)D tests. He then reviewed evidence of the 25(OH)D levels needed to prevent numerous cancers. The safest levels are somewhere above 50 ng/ml. Cedric spent most of his time presenting an entirely new theory of carcinogenesis, one dependent on vitamin D maintaining cellular junctions. I suspect this paper will also be reprinted in 20 years. The only disagreement I have is with his recommendation for cancer patients to start at fairly low doses. For reasons I recently explained, the risk benefit analysis indicates cancer patients should take 5,000 to 10,000 IU per day and they may have no time to lose. Why worry about the phantom of vitamin D toxicity if you may be dying of cancer? Just have your calcium checked along with frequent 25(OH)D levels. Get your levels up to 70-90 ng/ml if you have cancer.Does vitamin D treat cancer?The next speaker was Professor Bruce Hollis. He reviewed basic physiology of vitamin D and emphasized that the entire system is designed to deal with an excess not with an insufficiency of vitamin D. Numerous mechanisms are available in your body to prevent vitamin D toxicity but few are available to deal with insufficiency. Then he briefly mentioned one of the most important discoveries about vitamin D in the last few years, one where Professor Neil Binkley of the University of Wisconsin was senior author. (In the last four years, Professor Binkley has become a prolific vitamin D expert and I hope Carol Baggerly is able to get him to speak at some of the upcoming conferences she hopes to sponsor.) As I have pointed out before, Hollis and Binkley's crucial discovery was that the body doesn't start storing the parent compound, cholecalciferol, until 25(OH)D levels reach about 50 ng/ml. They showed, using basic steroid pharmacology, that 50 ng/ml should be considered the lower limit of adequate 25(OH)D levels.Hollis BW, Wagner CL, Drezner MK, Binkley NC. Circulating vitamin D3 and 25-hydroxyvitamin D in humans: An important tool to define adequate nutritional vitamin D status. J Steroid Biochem Mol Biol. 2007 Mar;103(3-5):631-4. Bruce kept the audience enthralled with a review of all the disease states that indicate 25(OH)D levels need to be much higher than they are now, that is, the multiple biomarkers that suggest the lower limit of 25(OH)D levels should be above 40 ng/ml and closer to 50 ng/ml. Then Professor Hollis spoke of his ongoing study in pregnant women and how he got approval to use 4,000 IU of vitamin D per day back in 2003, quite an accomplishment. He also reviewed another one of his research projects, one that answered an age old question, why is breast milk a poor source of vitamin D? How were prehistoric infants supposed to get their vitamin D, by lying out in the sun where saber tooth tigers would eat them? No, they were hidden in caves and had to have another source or the human race would have died out long ago because rickets destroys a woman's and infant's chance to live through childbirth due to rachitic deformations of the mother's pelvis. Carol Wagner and Bruce Hollis, together with their colleagues, answered that age old question, human breast milk is a poor vitamin D source because virtually all modern mothers are vitamin D deficient. That is, when pregnant women keep their levels where we think prehistoric human levels were, about 50 ng/ml, breast milk becomes a rich source of vitamin D. First Carol and Bruce gave 2,000 IU per day, then 4,000 IU per day and finally 6400 IU of D3 per day to lactating women. Only at 6400 of D3/day did the women maintain both their own 25(OH)D levels and the levels of their breast feeding babies above 50 ng/ml. On 6400 IU/day, the vitamin D activity of the breast milk went from about 80 to 800 IU/L. Quite a discovery, and another reason for all of us to keep our levels above 50 ng/ml.Wagner CL, Hulsey TC, Fanning D, Ebeling M, Hollis BW. High-dose vitamin D3 supplementation in a cohort of breastfeeding mothers and their infants: a 6-month follow-up pilot study. Breastfeed Med. 2006 Summer;1(2):59-70.Professor Robert Heaney went last, discussing 74 slides. So much of what we know about vitamin D today is due to Robert's unceasing dedication to vitamin D, the most recent example being his and Joanne Lappe's randomized controlled trial showing that increasing baseline levels from 29 to 38 ng/ml reduced the risk of getting cancer by around 70%. He again pointed out that the body does not begin to consistently store much vitamin D until your levels get to around 50 ng/ml. He also went through multiple biomarkers of vitamin D. That is, what level or intakes do you have to have to reduce the incidence of multiple diseases? He covered calcium absorption, osteoporosis, risk of falling, muscle function, death and disability of the aged, TB, influenza, cardiovascular disease, hypertension, diabetes, cancer, multiple sclerosis, and gum disease. How can one vitamin be involved in so many diseases? Simple said Dr. Heaney, "vitamin D is the key that unlocks the DNA library." He then reviewed toxicity and concluded there is no evidence that it occurs at levels below 200 ng/ml or with intakes (total) below 30,000 IU per day. Of course, we have no reason to think anyone needs 30,000 IU per day or levels of 200 ng/ml, which would be irresponsible. But someone with a serious cancer should consider getting their level up to 70-90 ng/ml and that may take 10,000 IU per day or even more in some people. As a rule of thumb, 1,000 IU will raise 25(OH)D levels by about 10 ng/ml. Then Professor Heaney addressed a public health question. How much would we have to give all Americans to get 98% of people above 32 ng/ml without causing toxicity in anybody? The answer: 2,000 IU per day. Of course 32 ng/ml is not adequate but it would be a great first step. Furthermore, of the people left out, a high percentage would be African Americans. In fact, Dr. Talwar recently reported that 40% of African American women fail to achieve a level of 30 ng/ml even after taking 2,000 IU/day for a year.Talwar SA, Aloia JF, Pollack S, Yeh JK. Dose response to vitamin D supplementation among postmenopausal African American women. Am J Clin Nutr. 2007 Dec;86(6):1657-62.He also discussed his recent study giving healthy adults 100,000 IU as a single dose. If you start with a baseline level of 28 ng/ml and take 100,000 IU as a single dose, mean levels will remain above 32 ng/ml for two months. If you rely on such stoss doses, but you start with a lower level, or want your levels above 50 ng/ml, how often do you need to take 100,000 IU? We don't know the answer to the last question but we know that Grey et al gave 50,000 IU per week for four weeks then 50,000 per month for a year to 21 patients with hyperparathyroidism. Blood levels rose from a mean of 11 ng/ml at baseline to 30 ng/ml at one year and levels did not continue to rise after six months. Remember, that means half the patients had levels lower than 30 ng/ml at the end of the year. Also remember that the metabolic clearance (how quickly you use it up) might be higher in certain disease states.Grey A, et al. Vitamin D repletion in patients with primary hyperparathyroidism and coexistent vitamin D insufficiency. J Clin Endocrinol Metab. 2005 Apr;90(4):2122-6. That last point, metabolic clearance, is only one of a number of reasons that patients vary in their response to vitamin D. Remember, a surprising number of patients will tell their physician they are taking vitamin D when they are not, some will be taking preparations that have less in it than the label says, some will not absorb it, and some people weigh more than others. As Dr. Heaney points out, even if you know patients took 100,000 IU, great variably exists in individual response. At the end of two months some will have shown a minimal response and other much more. This is a field where little is known. Do different disease states use up vitamin D quickly? The answer is probably yes. Furthermore, variability also exists in how one metabolizes and catabolizes (breaks down) vitamin D. Also, what is the interactive effect of drugs that use the same liver enzymes for catabolism? We just don't know and that is why vitamin D blood testing is crucial. Remember, the only test to have is a 25-hydroxy-vitamin D. Do not let anyone get a 1,25-dihydroxy-vitamin D; it will not tell you if you are vitamin D deficient and is usually only indicated in evaluating high blood calcium.As far as 25(OH)D levels go, many of you have written complaining about the high cost of a 25(OH)D levels at some labs. I've got some good news. For the next month, Life Extension Foundation is having a sale on their 25(OH)D blood tests, only $32.25, including the fee for drawing the blood. (No, we don't get funding from Life Extension, I wish we did.) Life Extension uses LabCorp, which, in turn, uses an accurate method to determine 25(OH)D levels, the DiaSorin Laiason method. The only problem is that DiaSorin, LabCorp, and Life Extension all say that 30 ng/ml is acceptable. It is not. Take enough vitamin D or get enough UVB radiation to get your levels above 50 ng/ml. To order the test, call Life Extension at 800 208-3444. Unfortunately, this offer is not available in New York, New Jersey or Rhode Island.Also, Dr. James Dowd has written a fine book about vitamin D, The Vitamin D Cure. Get this, he is board certified in internal medicine, adult rheumatology, and pediatric rheumatology, an associate professor at Michigan State University, and runs his own Arthritis Institute and the Michigan Arthritis Research Center. He gives a formula for how much vitamin D you need but stresses the impor CT scans and radiation exposure Toggle navigation Home Blog Home Archive Join Now Log in CT scans and radiation exposure 19. June 2007 William Davis (8) The NY Times ran an article called With Rise in Radiation Exposure, Experts Urge Caution on Tests at http://www.nytimes.com/2007/06/19/health/19cons.html?_r=1&adxnnl=1&oref=slogin&adxnnlx=1182254102-vQpytpx6W/Z9gvAaNPDZvA “This is an absolutely sentinel event, a wake-up call,” said Dr. Fred A. Mettler Jr., principal investigator for the study, by the National Council on Radiation Protection. “Medical exposure now dwarfs that of all other sources.”Where do CT heart scans fall?Let's first take a look at exposure measured for different sorts of tests:Typical effective radiation dose valuesComputed tomography Milliseverts (mSv)Head CT 1 – 2 mSvPelvis CT 3 – 4 mSvChest CT 5 – 7 mSvAbdomen CT 5 – 7 mSvAbdomen/pelvis CT 8 – 11 mSvCoronary CT angiography 5 – 12 mSvNon-CT Milliseverts (mSv)Hand radiograph Less than 0.1 mSvChest radiograph Less than 0.1 mSvMammogram 0.3 – 0.6 mSvBarium enema exam 3 – 6 mSvCoronary angiogram 5 – 10 mSvSestamibi myocardial perfusion (per injection) 6 – 9 mSvThallium myocardial perfusion (per injection) 26 – 35 mSvSource: Cynthia H. McCullough, Ph.D., Mayo Clinic, Rochester, MNIf you have a heart scan on an EBT device, then your exposure is 0.5-0.6 mSv, roughly the same as a mammogram or several standard chest x-rays. A heart scan on a 16- or 64-slice multidetector device, your exposure is around 1.0-2.0 mSv, about the same as 2-3 mammograms, though dose can vary with this technology depending on how it is performed (gated to the EKG, device settings, etc.)CT coronary angiography presents a different story. This is where radiation really escalates and puts the radiation exposure issue in the spotlight. As Dr. Cynthia McCullough's chart shows above, the radiation exposure with CT coronary angiograms is 5-12 mSv, the equivalent of 100 chest x-rays or 20 mammograms. Now that's a problem. The exposure is about the same for a pelvic or abdominal CT. The problem is that some centers are using CT coronary angiograms as screening procedures and even advocating their use annually. This is where the alarm needs to be sounded. These tests, as wonderful as the information and image quality can be, are not screening tests. Just like a pelvic CT, they are diagnostic tests done for legimate medical questions. They are not screening tests to be applied broadly and used year after year. Always be mindful of your radiation exposure, as the NY Times article rightly advises. However, don't be so frightened that you are kept from obtaining truly useful information from, for instance, a CT heart scan (not angiography) at a modest radiation cost. Detail on radiation exposure with CT coronary angiograms on multidetector devices can be found at Hausleiter J, Meyer T, Hadamitzyky M et al. Radiation Dose Estimates From Cardiac Multislice Computed Tomography in Daily Practice: Impact of Different Scanning Protocols on Effective Dose Estimates. Circulation 2006;113:1305-1310, one of several studies on this issue. Related posts Do heart scans cause cancer? Another in a series of data extrapolations that attempt to predict long-term cancer risk from medica... John Cannell on Vitamin D You can always count on Dr. John Cannell for unique perspectives on vitamin D. I reprint here his un... More on the American Heart Association Check Mark program Take a look at the list of foods on the American Heart Association's (AHA) Check Mark endorsement pr... Comments (8) - Anonymous 6/20/2007 1:13:00 AM | I had a calcium score scan on a 64-slice machine at the Morristown Hospital in New Jersey. No contrast was injected. The technician did three separate scans that included the lung, even thought I didn't for a lung scan. I wonder why three scans were taken. Does it mean that I had three times the radiation? Dr. Davis 6/20/2007 1:22:00 AM | Hi, Of course I can't comment specifically on what was done, but it is common practice to perform 1) a "scout" film for the technologist to identify the location of important "landmarks" like the sternum and the top and bottom of the heart to minimize the window of exposure, and 2) lung imaging as a routine part of heart imaging, not necessarily an additional scan. If an additional and unrequested lung scan was performed, you may want to call and ask why this policy is in operation. Anonymous 6/21/2007 4:35:00 AM | What do you feel about yearly nuclear stress tests for people with CAD? The radiation exposure seems high and the ability of a stress test to pick subtle changes in flow is low. In the absence of symptoms it would appear that the common practice of nuclear stress tests for people with CAD is a questionable practice. Dr. Davis 6/21/2007 12:14:00 PM | I agree. The radiation is excessive. I tend to follow that route only when nothing else is possible. An alternative for stress testing is stress echocardiogram in its various forms, none of which involve radiation. They still suffer the other pitfalls of stress testing, of course, but do not involve radiation. Mike 12/20/2008 11:40:00 AM | I just launched a webiste that may answer some of your questions. www.xrayrisk.com. It allows you to calculate your cancer risk based on studies you have had and answers some faq on radiation exposure and cancer. Anonymous 12/6/2009 12:52:26 AM | There are several ways to estimate your cancer risk - the best site for background information is probably the Image Gently campaign.The American College of Radiology has similar information pages for patients and the general public.To track your exposure, as Mike said there's the xrayrisk website.There's also a program for the iphone called Radiation Passport that tracks all of your radiation exposure and gives you the associated risk of developing cancer from your radiation exposure. buy jeans 11/3/2010 6:33:12 PM | CT coronary angiography presents a different story. This is where radiation really escalates and puts the radiation exposure issue in the spotlight. As Dr. Cynthia McCullough's chart shows above, the radiation exposure with CT coronary angiograms is 5-12 mSv, the equivalent of 100 chest x-rays or 20 mammograms. Now that's a problem. Medical CT 11/29/2010 4:34:03 AM | The CT scanner was originally designed to take pictures of the brain. Now it is much more advanced and is used for taking pictures of virtually any part of the body.The scanner is particularly good at testing for bleeding in the brain, for aneurysms (when the wall of an artery swells up), brain tumours and brain damage. It can also find tumours and abscesses throughout the body and is used to assess types of lung disease. Add comment Comment Preview Name * E-mail * Comment * Preview Notify me when new comments are added The captcha text was not valid. Please try again.
CT scans and radiation exposure 19. June 2007 William Davis (8) The NY Times ran an article called With Rise in Radiation Exposure, Experts Urge Caution on Tests at http://www.nytimes.com/2007/06/19/health/19cons.html?_r=1&adxnnl=1&oref=slogin&adxnnlx=1182254102-vQpytpx6W/Z9gvAaNPDZvA “This is an absolutely sentinel event, a wake-up call,” said Dr. Fred A. Mettler Jr., principal investigator for the study, by the National Council on Radiation Protection. “Medical exposure now dwarfs that of all other sources.”Where do CT heart scans fall?Let's first take a look at exposure measured for different sorts of tests:Typical effective radiation dose valuesComputed tomography Milliseverts (mSv)Head CT 1 – 2 mSvPelvis CT 3 – 4 mSvChest CT 5 – 7 mSvAbdomen CT 5 – 7 mSvAbdomen/pelvis CT 8 – 11 mSvCoronary CT angiography 5 – 12 mSvNon-CT Milliseverts (mSv)Hand radiograph Less than 0.1 mSvChest radiograph Less than 0.1 mSvMammogram 0.3 – 0.6 mSvBarium enema exam 3 – 6 mSvCoronary angiogram 5 – 10 mSvSestamibi myocardial perfusion (per injection) 6 – 9 mSvThallium myocardial perfusion (per injection) 26 – 35 mSvSource: Cynthia H. McCullough, Ph.D., Mayo Clinic, Rochester, MNIf you have a heart scan on an EBT device, then your exposure is 0.5-0.6 mSv, roughly the same as a mammogram or several standard chest x-rays. A heart scan on a 16- or 64-slice multidetector device, your exposure is around 1.0-2.0 mSv, about the same as 2-3 mammograms, though dose can vary with this technology depending on how it is performed (gated to the EKG, device settings, etc.)CT coronary angiography presents a different story. This is where radiation really escalates and puts the radiation exposure issue in the spotlight. As Dr. Cynthia McCullough's chart shows above, the radiation exposure with CT coronary angiograms is 5-12 mSv, the equivalent of 100 chest x-rays or 20 mammograms. Now that's a problem. The exposure is about the same for a pelvic or abdominal CT. The problem is that some centers are using CT coronary angiograms as screening procedures and even advocating their use annually. This is where the alarm needs to be sounded. These tests, as wonderful as the information and image quality can be, are not screening tests. Just like a pelvic CT, they are diagnostic tests done for legimate medical questions. They are not screening tests to be applied broadly and used year after year. Always be mindful of your radiation exposure, as the NY Times article rightly advises. However, don't be so frightened that you are kept from obtaining truly useful information from, for instance, a CT heart scan (not angiography) at a modest radiation cost. Detail on radiation exposure with CT coronary angiograms on multidetector devices can be found at Hausleiter J, Meyer T, Hadamitzyky M et al. Radiation Dose Estimates From Cardiac Multislice Computed Tomography in Daily Practice: Impact of Different Scanning Protocols on Effective Dose Estimates. Circulation 2006;113:1305-1310, one of several studies on this issue.