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Vitamin D Deficiency Behind Many Western Cancers?
twilight30 wrote us with a link to an article in the Globe and Mail. If further study bears out the findings, new research into the causative agents behind disease and cancer may have a drastic impact on the health of citizens in Canada and the US. According to a four-year clinical trial, there's a direct link between cancer and Vitamin D deficiency. "[The] trial involving 1,200 women, and found those taking the vitamin had about a 60-per-cent reduction in cancer incidence, compared with those who didn't take it, a drop so large — twice the impact on cancer attributed to smoking — it almost looks like a typographical error. And in an era of pricey medical advances, the reduction seems even more remarkable because it was achieved with an over-the-counter supplement costing pennies a day. One of the researchers who made the discovery, professor of medicine Robert Heaney of Creighton University in Nebraska, says vitamin D deficiency is showing up in so many illnesses besides cancer that nearly all disease figures in Canada and the U.S. will need to be re-evaluated. 'We don't really know what the status of chronic disease is in the North American population,' he said, 'until we normalize vitamin D status.'"
TFA: >Referring to Linus Pauling, the famous U.S. advocate of vitamin C use as a cure for many illnesses, he said: "Basically, Linus Pauling was right, but he was off by one letter."
OK, who else had the feeling that they were going to bash vitamin C before the end of the article?
Get naked and get out! you know.. for Vitamin D synthesis.
The cancers are different and have different risks. As the article says, by limiting exposure to sunlight you're trading skin cancer (which is easily detected, quite easily treated and often not fatal) for the scarier cancers like bowel cancer which are implicated in a lot more deaths.
I believe that Vitamin D might protect against some cancers.
However, I do not agree that Vitamin D deficiency can be responsible for about 60% cancers.
Here are my reasons why:
1) The process of carcinogenesis (initiation of the first DNA mutation/ adduct required to form cancer to the stage of clinically overt disease) in most cases takes more than 4 years. This clinical trial is only 4 years and too premature to reach to conclusions.
2) I have yet to read the paper, but it is necessary to know whether this trial was truly randomized meaning that the those who got the Vitamin D pill and those who got the placebo were similar to each other in all other ways. It is possible that if it is not randomized, a healthier cohort of people chose to take Vitamin D for a long time.
3) It is also important to know how they treated those people who dropped out of taking the Vitamin D pills. It is possible that unhealthier people dropped out and then we were comparing all subjects in the placebo group to the "healthier" people in the Vitamin D group.
4) A risk reduction of 60% (= relative risk of 0.4) is epidemiologically very strong and if that was the case, we would have already found such a role of Vitamin D much earlier (like 30 years before or so). There is something called Bradford Hill's criteria for causation in epidemiology which has strength of association as one of the criteria. The rationale for that is if we had a confounder which is actually responsible for the effect, we would have known it before because it is more likely to have a stronger effect. The same principle goes here. We do not know anything that could prevents so many types of cancer with such great attributable fraction. The magnitude of effects of like 2.5 or reduction of risk to 0.4 were the strengths we used to see in the papers of 1970s. Hence I think there could be some issues with the study design and data analysis of this study if they found such a great magnitude of effect.
Having said that I think that Vitamin D might prevent many cancers, but I expect a lower magnitude of the effect.
Not so fast ;)
Vitamin D is a fat soluble vitamin and is present in meat products. Deficiency in Vitamin D causes rickets. Vitamin D is so-called, and many would think it was not available without a dietary source, but it is produced in the skin under the influence of UV light. It then gets processed by the liver, then 'activated' in the kidneys and off it goes and does good things.
Because it is fat soluble, it is unlike Vitamin C in that stores are steady and no Vitamin D production only starts to cause problems after several months.
Whilst Vitamin D requirements increase with age, sun exposure commonly decreases with age, especially in the elderly. Much of this is simply a lifestyle issue.
Importantly, Vitamin D is already known to have immunomodulatory activities (a well functioning immune system is critical in preventing cancer over time). It is also known to induce some cancers to self-destruct.
Do it yourself, because no one else will do it yourself. [beta blockade 10-17 Feb]
Hmm, bash, C and linus in one sentence and it isn't about Linux.
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Yep.
You also forgot to add that besides a number of major cancers Vitamin D defficiency also has clear links to obesity as well. Its defficiency in childhood results in soft tissue growth overtaking bone development and very quickly going down the fat kid spiral. Nearly every obese kid aged 7-14 has classic X legs which are a clear indication that he/she has gone through vitamin D defficiency at some point in their life (usually past the age of 2, earlier results in O-shape). For every 1 person the "Dip your child into factor 40 cream" cretins save from skin cancer tens will die of other vitamin D defficiency related illnesses.
Just look at Australia. It was the first to go into the "hide in the shade" overdrive and we constantly get Australian studies quoted about the dangers of sun onto us (without any corrections for the fact that the numbers should be corrected for different lattitudes). It now is the world leader in obesity overtaking the US.
It is proudly followed by surprise surprise - UK which has taken all AU studies and is applying them blindly despite being at way further from the Equator. It is quite funny, every time I get some "scary" number quoted I ask the origin and it ends up being Australia from the height of the Ozone hole period. In the UK there is a further complicating factor - GP incompetence. None of the UK GPs and health visitors carries out the standard checks for rachitis on children. Further to this, if you ask them they tell you not to worry. If a child in the age 3-18 months get an abnormal hair loss, they tell you to go get special shampoo for him instead of running blood tests (which the rest of EU does).
Baker's Law: Misery no longer loves company. Nowadays it insists on it
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Name one race from a northern climate that has brown or black skin. You can't. There aren't any. Now name a race from an equatorial region that has white or light skin. Once again, you can't.
I'd say this is pretty strong evidence for the GP's point. Sure, there will be variations among races at the same latitude, I wouldn't be surprised if some equatorial people were darker than others. But I would also be surprised if there wasn't a STRONG correlation between latitude and skin color. It would seem really, really unlikely that this was "caused by genetic variation of a few settlers." Yeah, the light colored setters just randomly happened to move north, and the darker people stayed south. Sure.
And people weren't in northern europe long enough for evolution to have played a role? OK then how about China? Northern Chinese are very light-skinned, I know this from experience. And surprise, surprise - southern Chinese are alot darker. And don't you think that a 60% greater chance of disease due to vitamin D deficiency would be a strong evolutionary pressure? Strong enough to act over relatively short time periods on the evolutionary scale perhaps?
Anyway, if your evidence for this evolutionary biologists' "dismissal" of skin color's correlation to latitude is one book, that's pretty weak. Of course, it's still more evidence than I can submit.
Did you notice the link in the article to the vitamin D council?
Did you notice the doctor who did the study is part of the vitamin D council?
Although they are a non profit, they do provide links to lots of people who will be happy to sell you some vitamin D.
I work for a small biotech company that has been doing cancer research and we never put out a press release every time we think we are on to something interesting or promising. We do study after study not just to establish a link, but to understand exactly how a compound may stop or prevent cancer.
I wish people would take more time to ensure they have lots of data to go on before saying they have found a "direct link"
And on another note, I find it hard to believe that so many people are deficient in vitamin D.
We may spend a lot more time indoors than our ancestors, but I feel confident I am getting enough sunlight and enough D in foods i consume.
Up until one or maybe two hundred years ago, this worked fine. Only the wealthy could afford to gorge themselves to dangerous levels of obesity. Today, for maybe $6, I can go to Burger King and get a Whopper, fries (King Size) and a Coke (King Size). According to BK's own meal-builder nutrition info, this meal has 1660 calories (650 from fat), 72 grams of fat, and 117g total sugars. And I didn't even put cheese on that Whopper. (And no Vitamin D as far as I can tell.) This is theoretically one out of three meals, supposedly totaling 2000 calories. In all likelihood, it's more like hald the day's calories than most. Meanwhile, the average modern American doesn't burn nearly as many calories Mr. Caveman did, since we survive by sitting in cubicles instead of hunting and gathering. Clearly, our ability to feed ourselves has improved to the point where the foods we naturally crave due to things coded in our genes thousands of years ago are actually harming us. For all the exotic things we can now eat because of technology, our range of nutrients sucks.
So it's hard to diet because as far as your body knows, that triple fudge brownie might be the the calories you burn not freezing to death tonight. And since you're body's so preoccupied with this now baseless fear of starvation, it forgets to make you want to eat things like broccoli or spinach, which our ancestors were probably eating to pass the time until some meat wandered close enough to kill. Call it evolutionary sabotage- what we needed before is not what we need now, and if we can't stay on top of those changes, we tend to die.
It's interesting to note that regardless of the type of cancer (save some of the forms of mesothelioma that you tie to chemical exposure) the majority of cancers can be traced back to oxidative stress. As a physician I've seen remarkable results with dropping the usual chemical approach and using super antioxidents such as Acai extracts and grape-seed extracts.) My fellow physicians need to get off of the chemical bandwagon and really do some research in this direction. Cheers, Nick
The reason I have heard cited for why people such as the Inuit, or Italians have darker skin is because of fish intake.
Coastal peoples, such as the Inuit, have a high intake of fish in their diet, and so get a lot of Vitamin D. Same goes for the Italians.
My guess for the Amazon natives having lighter skin would be that they live in the jungle? Not out in the plains, and so they would still be receiving less sunlight than people living in the Savannah. Just a guess, but it fits with the theory.
So, light skin is still associated with low Vitamin D levels. If there is strong sunlight, or a large amount of fish in the diet, darker skin is advantageous.
As an American I can only say this: focusing on Vitamin D (or any other single nutrient) as a factor in causing disease X or condition Y simply shifts our attention from the real problem. And that is the simple, undeniable, thoroughly-established fact that our diet sucks. Sucks on a Biblical scale. If more of us accepted that and made some (admittedly significant) changes to that dietary intake, there'd be one hell of a lot fewer people with cancers of any kind. Not to mention strokes, and heart attacks, and diabetes, and all of the other diet and obesity-related conditions from which we suffer. My mind is absolutely boggled by the sheer scale of health problems resulting from typical American fare, and I feel sorry for people in other countries that are adopting American food because they think it's better for them. Chances are, compared to their traditional diet ... it isn't.
... they're already seeing an increase in cancers, strokes, heart attacks and diabetes, but without the drugs and surgical techniques we use to try and compensate for the lifetime abuse of our bodies.
... or the outlook will not be good. So, I'm making those changes.
... that's fine so far as it goes. It doesn't go far enough for most of us. Not nearly far enough.
For example, my fiancee is North African, and her traditional meals are largely vegetarian with relatively few percent of calories from animal-derived foods. She's never had a health problem. Her grandmother is 103. Granted, the reason the average person from her country doesn't eat more meat is because they can't afford it, not because they have some inhibition about eating meat. Yet, the wealthier members of the population there are eating more and more American-style foods and guess what
Don't get me wrong: I'm glad they're researching the effects of insufficient Vitamin D reserves on cancer. We can just add that into our total body of knowledge about diet and health. But we really need to keep our minds on the big picture, which clearly says that we don't eat right. Too many people I know have suffered or died from what they ate over their shortened lifetimes. So here I am, now at the age where I have to take a good, hard look at my family history, and take stock of my future health. The conclusion I've reached is this: either I make some serious changes to what I eat, and the way I live
My father died of diabetic complications at the age of 62, and his doctor said to me "that's one possible future for you." It was an awful, painful, degenerative death that lasted several years. I don't want to go that way, and sometimes we have to accept that changing a few little things here and there aren't going to cut it. Taking some Vitamin D supplements, or getting some more Sun, or eating some more broccoli
The higher the technology, the sharper that two-edged sword.