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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.'"
Now I'm waiting for another research showing that the intake of vitamin D causes some other serious illness...
So typical.
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60%. That's not a small number. Consider the possibilities: 60% of cancer reduced, just by using a standard vitamin pill. I think I'll head off to the pharmacy.
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.
Yes. You see sunlight, like many things, too much of something can be lethal.
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.
How is this confusing? Not enough sunlight may cause vitamin D deficiency, too much may cause cancer. Not enough food and you starve to death, too much and you grow obese and suffer related ailments.
Life is about balance.
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.
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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.
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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.
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.
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
According to this article, there is. The article is well written, and quotes the reference on this particular point to be:
Angwafo FF. Migration and prostate cancer: an international perspective. J Natl Med Assoc 1998 Nov; 90 (11 suppl):S720-3.
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....
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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.
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.
Nor that you could predict the latitude where some ethnic groups lives, down to 1 precision, based only on skin colour.
What the parent says is that *there seems* to be some variation of skin colour which may follow some pattern which can be put in relationship with some factor like sunlight exposure. Like always with nature, there are never "nevers" or "always". Only "tendencies" and even if there's so much variation between skin colours, you can't deny that paler complexion are a little bit more frequent in region with less sunlight exposure.
Amazon natives MAY be a lot less dark than other people living in the equator, they ARE STILL a little bit more tanned than Swedish people.
Also the whole point of the original poster was to say that this tendency of distribution could be partly caused by the fact that on one hand, too much sunlight kills because UV are cancerigens, and not enough kills too because of Vitamin D deficiency. Thus people will tend to have skin colours grossly adapted to the region where they originate from even if there's a lot of variation (partly due to the fact that all this is recent history and there hasn't been enough time for selection to discriminate more strongly, in fact given the local climate variation and the degree of additional modulable protection produced by clothes it's not necessary that skin colour needs more adaptation for regions).
As a side note, in practical medicine, we do see, for example, occurence of some problems such as osteoporosis (brittle bones due to deficiency in vitamin D) happening with a higher frequency in women originating from northern Africa (skin "somewhat tuned" for high sun exposure by recent evolution, but hiding under too much clothes for religious reasons and not getting enough sun to produce vitamin D) than with european women (wear also a lot of clothes for cold / sunburn protection, but the light that gets through paler skin is a little bit more for Vitamin D synthesis).
But on the other hand both gets way much more sun than people in Denmark. Or northern China. Or Siberia.
And happen to be, on the average, darker than those people, even if there's variation than can't be only explained by the amount of sun exposure alone.
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I don't think you're being dishonest, but Dermatologists would disagree with you.
According to the Gilchrest article I cited, Dermatologists believe that no amount of exposure to summer sun is completely safe, since the UV needed to produce vitamin D is exactly the same range of frequencies that cause DNA damage and skin aging. Also, according to this article, not only is oral vitamin D just as effective as that produced by the body, but in fact all of the large studies that show benefits of higher doses of vitamin D have been conducted using oral vitamin D. To quote from the abstract of the study cited in the original post, "it was achieved with an over-the-counter supplement costing pennies a day".
The Gilchrest article also points out that you can get the full vitamin D benefit from sunlight even if you use a high SPF sunscreen, since you only need the equivalent of a few minutes unprotected exposure. Tans are pretty, but there is a cost that is paid later in life.
Humans are opportunistic scavengers. We are capable of chasing down the weak and ill animals, we have a greater natural stamina than wolves, horses, zebras, bison, deer, oxen, and many other animals. Our teeth have grown smaller because we cook our food, however humans are quite capable of killing many animals with our bare hands. We also have been tool users for millions of years, and our bodies have adapted to this as well. Indeed the most violent and sadistic tribes enjoyed killing animals. And they got significantly better nutrition than those that do not. The nearest related species to humans also is an opportunistic omnivore, though they do eat much more plant matter. Chimps hunt and kill birds, smaller primates, and even members of other chimp troops. They readily eat termites, and even make tools to get them. So, anyone who says that humans are herbivores is woefully lacking in their understanding of comparative biology, and usually blinded to the truth by dogmas of certain religions that believe that harming animals harms the soul. If you look at the way that food is prepared, you'll even notice that humans prefer their meat to be slightly decayed, such as aged beef. Also cooking accelerates non-biotic breakdown of the muscle tissues, making them easier to digest for fat and protein It also kills the very bacteria that we like to partially predigest our food for us. As to the constipation angle, we are omnivores. We do eat vegetable matter as well as animal matter, which cancels this out. And many of the organisms that live in rotting meat (which as I've stated, is what is preferred by humans) can cause dysentery, so it's not as big of a deal as you'd think. Anyway, I'm done with my rant, and I've got karma to burn. Respond or not. I don't really care.
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