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Thread: Vitamin D fights cancer in absence of Vitamin A

  1. #1
    Administrator Islander's Avatar
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    Default Vitamin D fights cancer in absence of Vitamin A

    http://www.foodconsumer.org/
    27/02/2010
    Remarkable Paper in British Medical Journal
    This is a periodic newsletter from the Vitamin D Council, a non-profit trying to end the epidemic of vitamin D deficiency. If you want to unsubscribe, go to the end of this newsletter. If you are not subscribed, you can do so on the Vitamin D Council's website.

    A few weeks ago, the British Medical Journal published a remarkable paper, remarkable that it studied more than 500,000 subjects, remarkable that it had 56 (fifty-six) authors, remarkable that it confirmed low vitamin D levels obtained in the past are a risk factor for developing colon cancer in the future. However, the most remarkable part of the paper is that the 46 scientists minimized the true significance of their own research. They found that vitamin A, even in relatively low amounts, appears to thwart vitamin D's association with reduced rates of colon cancer.
    Jenab M et al. Association between pre-diagnostic circulating vitamin D concentration and risk of colorectal cancer in European populations: a nested case-control study. BMJ 2010;340:b5500
    This is a prospective nested case-controlled study, which means it uses subject's vitamin D blood samples obtained and frozen in the past and then reviews their medical records into the future to see who gets colon cancer, comparing the study subjects to similar members of the group that did not get the illness. Dr. Mazda Jenab and his 45 colleagues from the International Agency for Research on Cancer confirmed that low vitamin D levels are a risk for colon cancer in a dose response manner; those with the highest levels were about twice as less likely to develop colon cancer compared to those with the highest levels.
    However, hidden on page eight is one sentence and a small table, which shows that the benefits of vitamin D are almost entirely negated in those with the highest vitamin A intake. And the retinol intake did not have to be that high in these older adults to begin to negate vitamin D's effects, about 3,000 IU/day. Remember, young autistic children often take 3,500 IU of retinol a day in their powdered multivitamins, which doesn't count any additional vitamin A given in high single doses.
    This is the largest study to date showing vitamin A blocks vitamin D's effect and explains some of the anomalies in other papers on vitamin D and cancer. For example, Dr. Rachael Stolzenberg-Solomon of the NIH conducted two similar studies on pancreatic cancer, with startling different results. Her first paper showed high vitamin D levels tripled the subsequent risk of pancreatic cancer, her second paper showed no effect. The difference, the first was conducted in a cod liver oil country, Finland, the second in the USA.
    Stolzenberg-Solomon RZ et al. A prospective nested case-control study of vitamin D status and pancreatic cancer risk in male smokers. Cancer Res. 2006 Oct 15;66(20):10213-9.
    Stolzenberg-Solomon RZ, et al. Serum vitamin D and risk of pancreatic cancer in the prostate, lung, colorectal, and ovarian screening trial. Cancer Res. 2009 Feb 15;69(4):1439-47.
    Prostate cancer is another good example; ten similar studies have been conducted on vitamin D blood levels and the risk of subsequent prostate cancer. Dr. Lu Yin of the German Cancer Research Center reviewed them in detail. Eight of the studies found no relationship but two studies found a U shaped curve, that is, an increased risk of prostate cancer at both lower and higher vitamin D levels. You guessed it; both of these studies were from Nordic countries where cod liver oil consumption is rampant.
    Yin L et al. Meta-analysis of longitudinal studies: Serum vitamin D and prostate cancer risk. Cancer Epidemiol. 2009 Dec;33(6):435-45.
    So why is there no relationship between vitamin D levels and the future risk of prostate cancer? All the subjects had their vitamin D levels checked in the late 1980s or 1990s, well into the sun-scare but before the vitamin D revolution. So how did these older people get high levels of vitamin D back then? Multivitamins? No, they only contained a meaningless 400 IU. Vitamin D supplements? No, they were not widely available back then and only contained a meaningless 200 to 400 IU of vitamin D if available. Sunshine? Maybe, but I doubt it. Studies have shown that the elderly were the first to abide by sun-avoidance advice; anyway, the elderly lose the ability to make vitamin D from sunshine; it takes the elderly up to ten times more time in the sun that the young to make an equivalent amount of vitamin D.
    However, the elderly of many countries, not just Nordic countries, were raised on cod liver oil and I suspect that a sizable number of Americans continue to take cod liver oil as they age. While cod liver oil from the 1980s and 90s had higher amounts of vitamin D than does modern cod liver oil, it still had toxic amounts of A. I suspect if authors of the above ten studies had controlled for cod liver oil intake, they would have found that high retinol intake was blocking the cancer-preventing effects of vitamin D.
    I say this because one author has controlled for retinol intake and the pre-cancerous condition, colon adenomas. Dr. Kyungwon Oh, of the Korea Centers for Disease Control and Prevention, working with Harvard epidemiologists, found that high retinol intake completely thwarted the beneficial effects of vitamin D, stating, "a higher retinol intake, approximately > 4,800 IU/day, appears to counter the beneficial effect of vitamin D . . ." In other words, exactly what the British Medical Journal paper found with colon cancer.
    Oh K et al. Calcium and vitamin D intakes in relation to risk of distal colorectal adenoma in women. Am J Epidemiol. 2007 May 15;165(10):1178-86.
    Let"s look at Dr. Pamela Goodwin"s study from the University of Toronto that studied breast cancer survival. This a very different study as it looked at vitamin D levels obtained after the diagnosis of breast cancer and subsequent survival in 535 Toronto women between 1989 and 1996. Vitamin D levels ranged from 3 ng/ml to 70 ng/ml. The women with the lowest levels were about twice as likely to die and to suffer distant cancer recurrence compared those with the highest levels. Ten year survival was 85% for those in the upper one-third of vitamin D levels compared to 74% in the lower one-third. However, the data suggested a U shaped curve for the women with levels above 40 ng/ml, that is, a higher risk of dying, but it was not statistically significant.
    Goodwin PJ et al. Prognostic effects of 25-hydroxyvitamin D levels in early breast cancer. J Clin Oncol. 2009 Aug 10;27(23):3757-63.
    Again, let"s ask where women would get levels above 40 ng/ml in Toronto between 1989 and 1996? Sunshine? We know the answer is no as the authors found no seasonal variation in 25(OH)D levels in the 535 women, even in the women with the highest levels. So where did blood levels of 40-70 ng/ml come from in the early 1990s? Vitamin D supplements were not widely available in the early 1990s, and only contained meaningless doses when available. As sunshine was ruled out, they could only have gotten it from cod liver oil. I have emailed Dr. Pamela Goodwin, lead author, asking how hard it would be to see if cod liver oil use was asked about in the dietary questionnaire and if she could control for cod liver oil intake. She did find retinol intake was associated with higher vitamin D levels but I am particularly interested in cod liver oil intake in women with vitamin D levels above 40 ng/ml.
    It's not just in breast cancer that vitamin D levels appear to have a treatment effect; it's in lung, prostate and colon cancer as well. Again, these are studies of people diagnosed with cancer to see if high vitamin D levels at the time of diagnosis are associated with improved survival.; that is, do high vitamin D levels have a treatment effect? On average, those with the highest vitamin D levels at time of diagnosis lived 2 or 3 times longer. One has to ask how high vitamin D levels are associated with greatly improved survival once you get cancer but a higher risk of getting cancer in the first place. That requires some gymnastic thinking and acrobatic basic science.
    Zhou W et al. Circulating 25-hydroxyvitamin D levels predict survival in early-stage non-small-cell lung cancer patients. J Clin Oncol. 2007 Feb 10;25(5):479-85.
    Ng K et al. Clin Oncol. 2008 Jun 20;26(18):2984-91. Circulating 25-hydroxyvitamin D levels and survival in patients with colorectal cancer. J Clin Oncol. 2008 Jun 20;26(18):2984-91.
    Tretli S et al. Association between serum 25(OH)D and death from prostate cancer. Br J Cancer. 2009 Feb 10;100(3):450-4.
    Remember, studies of vitamin D levels and subsequent risk of cancer are only one type of epidemiological study. Studies of latitude and cancer are quite clear, the less sunshine the higher the cancer risk. Studies of dietary vitamin D intake and cancer are also mostly supportive but such studies are limited by the tiny doses people get in their diets.
    So it is not just autistic children that are being harmed by vitamin A. Avoid cod liver oil like the poison it is and check your multivitamins. Life Extension Foundation just reformulated their multivitamin to contain only 500 IU of preformed retinol. And, I am happy to report that Purity Products, which markets my vitamin D, has no preformed retinol at all in any of their multivitamins, only beta carotene. Purity has also stopped selling cod liver oil. Now, if only Carlson, Solgar, Nature's Way, and other companies would stop selling cod liver oil and stop selling their concentrated vitamin A supplements to a country whose problem is widespread sub-clinical vitamin A toxicity, I'd be a happier agitator.
    John Cannell, MD
    Executive Director
    Vitamin D Council

    Remember, we are a non-profit and rely on your donations to publish our newsletter, maintain our website, and pursue our objectives. Send your tax-deductible contributions to:
    The Vitamin D Council
    1241 Johnson Ave., #134
    San Luis Obispo, CA 93401

    http://tinyurl.com/yhndu6j

  2. #2
    Veteran Member mellowsong's Avatar
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    Default Re: Vitamin D fights cancer in absence of Vitamin A

    I don't know what to think of this. I do know that the ratio of D to A is critical but I don't see that mentioned. Vitamin A is essential for vision, for bone health, for formation/maintenance of mucous membranes, healthy hair and skin. It is also necessary to proper functioning of the immune system.

    The Vitamin D council has been attacking cod liver oil for a few years now. The WAP Foundation posted a rebuttal to this attack. I think this condemnation of Vitamin A is possibly more opinion than fact. Again, in studies, it is virtually impossible to account for all variables so is CLO/Vitamin A necessarily the culprit? Statements such as use of CLO is "rampant" and "I suspect that a sizable number of Americans continue to take cod liver oil as they age" are far from scientific.

    I tend to think the ratio of A to D is more important than just the Vitamin A itself. Per WAPF, the ratio of A to D should be no greater than 10:1. In other words, for every 10 units of Vitamin A taken, you should take a minimum of 1 unit of Vitamin D.

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    Administrator Islander's Avatar
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    Default Re: Vitamin D fights cancer in absence of Vitamin A

    Mellowsong, I've read the same thing, but after posting this article I put away my bottle of Vitamin A. I'd really like to see this issue clarified by an objective source...although the results reported above seem to be based on exhaustive research. What am I missing?

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    Veteran Member mellowsong's Avatar
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    Default Re: Vitamin D fights cancer in absence of Vitamin A

    Quote Originally Posted by Islander
    Mellowsong, I've read the same thing, but after posting this article I put away my bottle of Vitamin A. I'd really like to see this issue clarified by an objective source...although the results reported above seem to be based on exhaustive research. What am I missing?
    I totally agree with you Islander on wanting to see it objectively clarified. I still don't know what to think. I don't believe the Vitamin D council is objective at all. The variables are what make me skeptical. Is the vitamin A from fish oil or synthetic; Finland is low sunshine so were they getting too much A in relation to D and on and on. This article simply says "highest" levels of intake, but doesn't specify a range of intake that put a person into an at risk group.

    With all that said, I have been taking 25,000 units/day for over 2 1/2 years. Although a recent blood test showed levels not even at the 1/2 point on the range, I'm going to cut down to 1 or 2 times/week.

    Because of Dr. Cannell's vicious attacks on WAPF, I tend to disregard about anything he has to say. I'm not saying WAPF is infallible by any means, just that I don't like Dr. Cannell's tactics. He has an agenda and I wouldn't put it past him to skew anything to fit his agenda. The Linus Pauling Institute says that the RDA of 2330 units for women and 3000 for men is adequate. This is probably sage advice.

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    Veteran Member Reesacat's Avatar
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    Default Re: Vitamin D fights cancer in absence of Vitamin A

    I think sticking with the Linus Pauling Institute recommendation is good advice.
    I do think Dr. Connell is pushing an adgenda.
    So far WAPF and LPI have issued recommendations that stand the winds of extremists and fads.
    Vitamins have to be in balance and sourced mostly from food.
    Last edited by Reesacat; 03-03-10 at 01:18 AM.

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    Administrator Islander's Avatar
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    Default Re: Vitamin D fights cancer in absence of Vitamin A

    Mellowsong, that seems like a lot of Vitamin A. Have you have your D levels tested recently, and where do you stand with that?

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    Veteran Member mellowsong's Avatar
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    Default Re: Vitamin D fights cancer in absence of Vitamin A

    Quote Originally Posted by Islander
    Mellowsong, that seems like a lot of Vitamin A. Have you have your D levels tested recently, and where do you stand with that?
    That amount of Vitamin A was recommended to me by my first chiropractor and the environmental doc I was seeing. My research convinced me toxicity was pretty much impossible at that dose and the ratio of A to D is good. However, the above article is a bit worrisome hence cutting down for now. D was tested the same time as the A and it is still 40. I have no idea where it was when I started in June of 2007, but in Feb 2009 it was 40 and in Jan 2010 it was 40. I take 5000 IU D/day. The doc told me to increase to 7500 but I'm leery of pushing it because of CFIDS.

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