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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.
OK. Skin cancer. The main source of vitamin D in humans is through exposure to sunlight. Increase that without being careful and your risk of skin cancer goes up. Also, vitamin D overdosing from supplements is entirely possible and does have nasty side effects, although it's not possible from natural production due to exposure to sunlight.
There we go, cynicism confirmed, and it wasn't as bad as all that. Now, let's get down to reality: as vitamins, the vitamin D group have been identified as essential for human nutrition. Not useful, essential. As in, we would die without it. There's strong evidence, in fact, that the reason people that moved away from the equator developed paler skin was to maintain high production rates of vitamin D. So, quite frankly, even if the intake of vitamin D killed us, we'd have to have it as if we don't take it we die anyway, therefore the entire point is moot.
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]
Let me see... People roll from their bed into their car (via a door between the house and the garage), drive to work and park under the building. Lunch in the canteen, and in the evening the same path and sitting in front of the TV. 90% of the people in the apartment block I'm living in does live this way and get no direct sunlight for weeks. I think I found the reason why people have a vitamin D deficiency!
bash$
Hmm, bash, C and linus in one sentence and it isn't about Linux.
Patents Drive Free Software as Hurricanes Drive Construction Industry
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
http://www.sigsegv.cx/
The doctor that I work for has asked me to research this very line of thinking for her, pulling every article out I could find on multiple sclerosis (MS) and Vitamin D, and I even ended up using some of that research in a paper I wrote for an English class.
There's a very significant link between Vitamin D deficiency and MS. Most MS cases occur in the far north and far south climes. Think of southern Australia and Tasmania and northern Europe and United States, areas where sunshine is at low levels for as much as nine to ten months out of the year. We are able to make Vitamin D via sun exposure on the skin, which for humans, is a primary source of Vitamin D. Some of these studies find that people who had high levels of sun exposure as children greatly reduces their risk of contracting MS.
Don't believe me? Read these studies. There are tons more just like them, confirming the suspicion.
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.
Our white skin color comes from the Caucasus mountains, north of Iran. That's why white people are called Caucasians. I had a woman friend whose ancestry was from northern Iran, and it was amazing to see how white she was, in a way I thought was beautiful. Comparing her skin and mine, it was easy to see that I am a mixture of Caucasian and something else.
Probably the reason northern people are white is that black people inter-marrying with a high concentration of white people tends to produce lighter-skinned new generations.
All humans apparently spread from an original migration from Africa, but the people who initially migrated tended to continue to migrate, and migrated much more than those who initially stayed in Africa.
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
Inuit... Inuit have relatively dark colored skins...
n uit-onto-thin-ice/2006/05/26/1148524886121.html
http://www.smh.com.au/news/world/climate-forces-i
And Inuit have been living in the North for many thousands upon thousands of years (50,000 I think). Actually I am always amazed at how dark their skin is comparing to where they live. It's not like you are going to see a bunch of Inuit suntanning on the tundra...
A skin near the equator that is light colored? Hmm... How about Amazon natives? http://bbs.keyhole.com/ubb/z0302a1700/amazon.jpg
The Amazon is about as close to the equator that you can get and their skin is relatively light colored when compared to say the skin color of an individual from Africa. And last I heard Amazon natives have been there for many many many thousands of years.
So the nutshell is equator = darkness of your skin color is HOGWASH! Want me to prove it even further? How about the aboriginals of Australia when compared to an individual from Malaysia? Aboriginals are much much darker and further away from the equator than individuals from Malaysia....
"You can't make a race horse of a pig"
"No," said Samuel, "but you can make very fast pig"
You do know that in addition to sunlight, Fatty fish and Fish Oils, a staple of Inuit diet, is a significant source of Vitamin D? Seems to me that they adapted to get their Vitamin D by an alternative source.
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.
Okay, after reading the entire hysterical FA, I want that ten minutes of my life back. A sensationalistic article published on a slow-news Sunday in the Globe and Mail (where I always look for good peer-reviewed scientific evidence) says that a study "will be published" in June that will revolutionize the way that I, a practicing physician, view chronic disease.
Or maybe not. I can't tell whether the study was prospective, controlled, or blinded. I can't tell what cancers were examined. I CAN tell you that four years is ridiculously short for a study examining the emergence of cancer, which appears (we're not sure yet) to take decades in most cases. Since the journal is not named, I don't know its reputation or whether the study was peer-reviewed (and by what peers). In other words, I have no information that allows me to evaluate the claim, except that the claim itself was published in the newspaper. This in itself is not a good sign.
It is a violation of scientific ethics to pre-announce your results in the lay press without also revealing the details of your methods and the limitations of your study. In the case of a "miracle" result for a common supplement, it rises to the level of being truly suspicious. Extraordinary claims really do require extraordinary proof, and making such a claim in a Sunday supplement in the complete absence of accompanying evidence is the stuff of psychics and snake oil.
I am skeptical. I am willing to be convinced, but I'm also willing to entertain cash bets on the probability of this being true and clinically useful.
That's funny, cause I taped some lectures at a major research institution back in '04 where an evolutionary biologist cited the link between skin color and latitude. So apparently not all evolutionary biologists subscribe to this belief.
Too little sun exposure causes a Vitamin D deficiency. When women have Vitamin D deficiencies, they become less fertile. And interestingly, if I recall correctly, too much sun exposure interferes with women's antral follicle development - the ones in the ovaries, not on the skin. Therefore, there is the potential for selective pressure to be both not too dark and not too light.
Is natural selection - note that I said Natural Selection, not evolution - fast enough to cause the suppression of darker-skinned people at the poles and lighter-skinned people at the equator? Well, if I started off with a population where everyone's blood type was either AB, A, or B, and I sterilized all of the people with B alleles, the population would soon be all type A. No other factor has as direct an impact on a population's genes than fertility, by definition. Forget skin cancer. Skin cancer won't prevent most people from having children. Having no viable eggs will.
So nobody's saying those strange cosmic rays created the variation we see in people's skin tones. But it's daft to push aside the direct impact that skin color and latitude have on fertility, and the large body of circumstantial evidence we have in the form of human geography.
Here are a few of them:
Humble, M. (2007). [Vitamin D deficiency probably more common than earlier apprehended. Prevention and treatment could result in unexpected public health effects]. Läkartidningen, 104(11), 853-7.
Nielsen, LR, & Mosekilde, L. (2007). [Vitamin D and breast cancer]. Ugeskrift for læger, 169(14), 1299-302.
Ondková, S, Macejová, D, & Brtko, J. (2006). Role of dihydroxyvitamin D(3) and its nuclear receptor in novel directed therapies for cancer. General physiology and biophysics, 25(4), 339-53.
Garland, CF, Gorham, ED, Mohr, SB, et al. (2007). Vitamin D and prevention of breast cancer: pooled analysis. The Journal of steroid biochemistry and molecular biology, 103(3-5), 708-11.
The results also makes sense in evolutionary terms.
A Good Troll is better than a Bad Human.
Several counter-points:
- Southern and particularly South Africa are HOT, very hot, and it's sunny almost every day of the year. Summer is baking hot for months. Rudimentary research would've turned that up.
- The black people of South Africa are here as a result of a relatively recent massive migration of the Bantu peoples from around the Cameroon area that spread first East and then South. In South Africa they have been here probably not more than 1500 years.
- The indigenous people of South Africa that have been here for a long time (10,000+ years), e.g. the Khoesan, DO in fact have lighter complexions than the Bantu peoples that came from the equatorial regions.
- Even the 'black' people of South Africa ARE in fact lighter than their self-same relatives from up North - in fact generally speaking the closer you get to the equator, the darker the black people get. (That itself appears to be another strong argument for the Vitamin D correlation, although it's not that cut and dry because some, or perhaps much, of the lightening of the blacks in South Africa is due to generations of interbreeding with e.g. Khoesan peoples.)
I have Vitamin D deficiency, and it came close to ruining my life. I am a scientist, but I also have dark skin that never burns. Even though I don't own a car, I just can't get the 2-3 hours of sunshine daily needed to fulfill my Vitamin D requirement; white folks only need 20 minutes. Moreover, it's kind of chilly where I live, so I wear long pants and sleeves much of the time.
Over time, I developed a pain that just sucked the life out of me -- like I was playing four quarters of football daily, with the flu. Even with powerful pain killers I couldn't sleep, and woke up every day feeling I was hit by a bus.
The link to cancer is still an open question, but the pain is a hard fact.
PS: The only way to overdose on Vitamin D is to abuse prescription-strength supplements or cod liver oil.