I don’t have access to the full paper, but I would expect that they at least tried to control for sun exposure.
In general, if you can think of an obvious confounding factor in about five seconds, then it’s a safe assumption that professional researchers thought of it too.
Or, at least, a safer assumption: it's worth checking to see what they said about it before publicly speculating.
And indeed, it seems they did survey for sun exposure and include it in their analysis, and they caveat a lot of their references to other work in their introduction noting where other studies didn't.
> In general, if you can think of an obvious confounding factor in about five seconds, then it’s a safe assumption that professional researchers thought of it too.
I work in academic medicine. I read a lot of papers. This is not at all a given in my experience, except maybe in the tippy top journals (Nature, NEJM). When in doubt, read the paper, see if they mention the confounder you thought of.
They probably have, but that doesn’t mean they have the necessary data to actually address the confounds. Often there is a trade off between what is most provable and what is most novel. Publishing incentives being what they are, novel invariably wins.
The study is based on a couple hundred people in a city in Finland, they could at least have tried to collect data on people closer to the tropics to hedge a bit. I doubt this has any validity ignoring such a basic confounding factor like living in a place that does have a lot of sun exposure.
Accounting for confounders is hard. Otherwise randomised controlled studies wouldn't be needed, and we'd not have taken this long to walk back the consensus that red meat causes cancer.
Here is the description how they measured the impact of sun exposure to the results:
> The exposure of skin to UV radiation was clarified with different questions. The self-estimated lifetime exposure was studied with the following question ‘How often have you exposed yourself to sunlight during your lifetime?’ The answer options were (1) ‘seldom’, (2) ‘occasionally’, (3) ‘often’, or (4) ‘very often’. The sunburn history was studied with the following question: how often has your skin been burned due to sunlight during your lifetime? The answer options were (1) ‘seldom’, (2) ‘occasionally’, or (3) ‘often’. The answer options for the question of ‘Main environment in working history’ were (1) ‘outdoor’, (2) ‘indoor’, or (2) ‘variably both’.
They saw approximately the same distribution of sun exposure across the different test groups, it looks like.
I wish they asked exact rates and timelines. Like living in Florida, getting a bad burn only once per year might be considered seldom. But if you lived in Alaska, I’m sure that would be qualify as often.
I think just as likely is the general problem of people who take supplements being generally more conscientious and less likely to engage in risky behaviours (e.g. wearing sunscreen in summer)
Doctors recommend supplementing vitamin D if you have a measured deficiency. Most people naturally settle to 20 ng/mL or higher, and just incidental exposure, or eating certain foods can help you either absorb or synthesize it.
There are also people, like me, who no matter what, we can't make as much vitamin D for whatever cluster of genetic factors causes that. Some of us are always tired unless we take 50,000 IU of D3 a week.
The most plausible reason is that the scientific peer-reviewed result is correct, not the tiring "correlation does not imply causatian" commenter on HN who at most skimmed the paper.
2009:
> Epidemiological data show an inverse relationship between vitamin D levels and breast cancer incidence. In addition, there is a well-documented association between vitamin D intake and the risk of breast cancer. Low vitamin D intake has also been indicated in colorectal carcinogenesis. A vitamin D deficiency has also been documented in patients with prostate cancer, ovarian cancer, as well as multiple myeloma. Larger randomized clinical trials should be undertaken in humans to establish the role of vitamin D supplementation in the prevention of these cancers.
I see research on essential vitamins all the time on HN. It really makes you think. There's cohorts who will debunk the studies based on methodology or glaring flaws. There's cohorts who will provide anecdotal evidence in support. There's even cohorts who will bring up a history lesson/"conspiracy" we all forgot about.
It really makes you wonder about essential vitamins though. There's so many of these types of studies that continue to show benefits of getting the right amount of vitamin D, but there's equally enough noise to tell you that you don't need it.
But for countries like America, experts continue to weigh in that we don't get enough essential vitamins and minerals through our diets, so wouldn't it just be common sense that many people are deficient and therefore should supplement?
Wasn't this the entire controversy of Pauling for example when he pushed Vitamin C? That the RDA amounts are not enough and should be highly personalized?
> experts continue to weigh in that we don't get enough essential vitamins and minerals through our diets
First, would be better to list some specifics rather than "experts say". But even if so, saying that people don't get enough of some micronutrient X from food, it doesn't necessarily follow that supplementation with pills will lead to better health (except in some specific and extreme circumstances that rarely affect people these days, e.g. scurvy).
Second, this was not the entire controversy around Pauling's vitamin C fantasy. His recommended doses were orders of magnitude larger than recommended amounts - it wasn't just about being "more personalized". Nevermind that Pauling's vitamin C theories have been thoroughly disproven.
1. No, because the specifics change every week. One week you're deficient in fiber, the next Vitamin D. Look to the mainstream news or online articles for this ridiculousness.
One issue with supplementation is the food matrix effect - Yes, Vitamin deficiencies are associated with all kinds of badness, but just supplementing this one nutrient doesn't address the underlying problem and often doesn't improve clinical outcomes. Rather, the deficiency is an indicator of poor health satus and to be fixed by adjusting the dietary pattern.
That's the thing with a lot of vitamin d and c associations anyway.
I think it's absolutely bonkers - it really blows me away - that we have such debate on the effects of single molecules, studied for untold millions of human hours.
And yet many people think we can improve on nature; tinkering and toying with vastly more complex machinery and life, that we barely understand.
We are still discovering entire structures in the human body, ffs, yet are seemingly happy to allow vast monocultures of corporate and for-profit GM crops; 'trusting the science'.
The lies are as thin as our topsoil's gonna be soon. I love the idea of scientific progress, and understanding things, but this attitute of 'trust the men in white coats with everything even though we don't understand Vitamin C or D all that well' is truly mind-boggling.
*: I assume the people down-voting this think I'm talking smack on science - read again. I'm talking about scientism, and hubris, and appeals to authority. Which if you were paying any attention whatsoever the last 3 years you ought to know are big problems right now.
> we have such debate on the effects of single molecules
Most complex systems have simple limiters, almost by definition of the latter. You don’t need to solve fluid dynamics and combustion physics to understand that more air through a carburettor causes an internal combustion engine to run faster.
I can only read the abstract, but this doesn't look very solid at all. It's a self-reported non-randomized study, and an absurdly large number of participants has had some type of skin cancer (184 out of 276). This makes the results extremely susceptible to selection bias.
Nice to see more benefits of Vitamin D. Highly recommend the supplement for tech workers who spend a lot of time indoors. I take 125mcg/5000IU a day when I wake up and it's subtle, but I just feel a little better with it. Sports Research is a good brand (not affiliated).
Nothing better than getting some real sun though, especially in the morning.
A lot of people in the first world are heavily deficient in vitamin D, and deficiency is linked to a whole host of health issues and vulnerabilities. It's dirt cheap and essentially completely safe below toxicity levels (which are quite difficult to hit -
I take 10,000 IU daily, and even with that my bloodwork shows me in the lower quartile of the normal range).
Its metabolite is a steroidal hormone, so it's pretty obvious why it would be beneficial for anti-inflammatory purposes, but it also modulates some key cardiovascular gene expression, too.
That seems like far too much, especially if you ever go outside. In the UK doctors recommend no more than 1,000 IU/day during the winter months. Any more than that is only if you are actually deficient. It seems really hard to get clear answers on it, though. People taking 10x the recommended dose of something seems strange. It makes me think it's being stored somewhere that isn't your blood. It's fat-soluble after all. Why on earth would you take so much anyway?
Also, ask your doctor to get yours tested! A couple years ago, my D was on the low end (31.7ng/mL; 30-100 is normal). I've been taking 5000IU of D3 since then, and a lab last month had me at 59.1. That seems to be about the perfect dose for me, and it's dirt cheap.
I second the Sports Research brand it's my favorite based on their obvious careful choice of fillers.
Anyway, yes the full spectrum of the sun provides much more, not only UV for vitamin D but the red/infrared part of the spectrum which is great for cellular energy.
I don't know; vitamin D supplements may be mostly advised in places where there just isn't enough sun.
In Scotland we get insufficient sunshine to produce natural vitamin D for around 6 months of the year, and there's discussion about whether everyone should be supplementing to the point it's been mooted as an addition to the water supply.
That's relevant because nobody uses sun screen during those months. I wouldn't expect any kind of correlation through sheer lack of use.
I've been sunbathing consistently this season for 30-45 minutes 2-4 times a week as weather permits. Recently got my D level tested to see how it has been working and it came back at 51.6ng/mL - pretty happy with this result.
Unfortunately I cannot get full article access, but from the abstract it sounds like they did not control for actual sun exposure.
It would seem to me that those who self medicate with vitamin D are those who know they do not get sufficient sun exposure, and would necessarily also be those at reduced risk of melanoma.
Readit News
In general, if you can think of an obvious confounding factor in about five seconds, then it’s a safe assumption that professional researchers thought of it too.
And indeed, it seems they did survey for sun exposure and include it in their analysis, and they caveat a lot of their references to other work in their introduction noting where other studies didn't.
https://www.naturalhealthresearch.org/wp-content/uploads/202...
I work in academic medicine. I read a lot of papers. This is not at all a given in my experience, except maybe in the tippy top journals (Nature, NEJM). When in doubt, read the paper, see if they mention the confounder you thought of.
Research should be able to stand up to scrutiny. The scientific process depends on it.
Given the ongoing reproducibility crisis and plethora of garbage research coming out of academia, I’m not assuming anything about any research I see.
> The exposure of skin to UV radiation was clarified with different questions. The self-estimated lifetime exposure was studied with the following question ‘How often have you exposed yourself to sunlight during your lifetime?’ The answer options were (1) ‘seldom’, (2) ‘occasionally’, (3) ‘often’, or (4) ‘very often’. The sunburn history was studied with the following question: how often has your skin been burned due to sunlight during your lifetime? The answer options were (1) ‘seldom’, (2) ‘occasionally’, or (3) ‘often’. The answer options for the question of ‘Main environment in working history’ were (1) ‘outdoor’, (2) ‘indoor’, or (2) ‘variably both’.
They saw approximately the same distribution of sun exposure across the different test groups, it looks like.
There are also people, like me, who no matter what, we can't make as much vitamin D for whatever cluster of genetic factors causes that. Some of us are always tired unless we take 50,000 IU of D3 a week.
Tweedledum: Low Vitamin D weakens your immune system. Having a weakened immune system increases your odds of skin cancer.
2009: > Epidemiological data show an inverse relationship between vitamin D levels and breast cancer incidence. In addition, there is a well-documented association between vitamin D intake and the risk of breast cancer. Low vitamin D intake has also been indicated in colorectal carcinogenesis. A vitamin D deficiency has also been documented in patients with prostate cancer, ovarian cancer, as well as multiple myeloma. Larger randomized clinical trials should be undertaken in humans to establish the role of vitamin D supplementation in the prevention of these cancers.
It really makes you wonder about essential vitamins though. There's so many of these types of studies that continue to show benefits of getting the right amount of vitamin D, but there's equally enough noise to tell you that you don't need it.
But for countries like America, experts continue to weigh in that we don't get enough essential vitamins and minerals through our diets, so wouldn't it just be common sense that many people are deficient and therefore should supplement?
Wasn't this the entire controversy of Pauling for example when he pushed Vitamin C? That the RDA amounts are not enough and should be highly personalized?
https://www.ncbi.nlm.nih.gov/books/NBK56068/table/summarytab... (Recommendations)
https://www.nature.com/articles/s41430-020-0558-y (Deficiency Worldwide)
> experts continue to weigh in that we don't get enough essential vitamins and minerals through our diets
First, would be better to list some specifics rather than "experts say". But even if so, saying that people don't get enough of some micronutrient X from food, it doesn't necessarily follow that supplementation with pills will lead to better health (except in some specific and extreme circumstances that rarely affect people these days, e.g. scurvy).
Second, this was not the entire controversy around Pauling's vitamin C fantasy. His recommended doses were orders of magnitude larger than recommended amounts - it wasn't just about being "more personalized". Nevermind that Pauling's vitamin C theories have been thoroughly disproven.
2. Maybe consider looking at modern research. https://www.cancer.gov/research/key-initiatives/ras/ras-cent...
> Nevermind that Pauling's vitamin C theories have been thoroughly disproven.
Nothing in science is proven. Only re-evaluated.
That's the thing with a lot of vitamin d and c associations anyway.
And yet many people think we can improve on nature; tinkering and toying with vastly more complex machinery and life, that we barely understand.
We are still discovering entire structures in the human body, ffs, yet are seemingly happy to allow vast monocultures of corporate and for-profit GM crops; 'trusting the science'.
The lies are as thin as our topsoil's gonna be soon. I love the idea of scientific progress, and understanding things, but this attitute of 'trust the men in white coats with everything even though we don't understand Vitamin C or D all that well' is truly mind-boggling.
*: I assume the people down-voting this think I'm talking smack on science - read again. I'm talking about scientism, and hubris, and appeals to authority. Which if you were paying any attention whatsoever the last 3 years you ought to know are big problems right now.
Most complex systems have simple limiters, almost by definition of the latter. You don’t need to solve fluid dynamics and combustion physics to understand that more air through a carburettor causes an internal combustion engine to run faster.
Nothing better than getting some real sun though, especially in the morning.
Its metabolite is a steroidal hormone, so it's pretty obvious why it would be beneficial for anti-inflammatory purposes, but it also modulates some key cardiovascular gene expression, too.
BTW, did they tell you to back off or cut your dose? at 59 ng/mL you're in the danger zone.
Anyway, yes the full spectrum of the sun provides much more, not only UV for vitamin D but the red/infrared part of the spectrum which is great for cellular energy.
In Scotland we get insufficient sunshine to produce natural vitamin D for around 6 months of the year, and there's discussion about whether everyone should be supplementing to the point it's been mooted as an addition to the water supply.
That's relevant because nobody uses sun screen during those months. I wouldn't expect any kind of correlation through sheer lack of use.
Most men never use sunscreen, including those who spend a great deal of time outdoors. I seriously doubt that cohort takes vitamin D.
It would seem to me that those who self medicate with vitamin D are those who know they do not get sufficient sun exposure, and would necessarily also be those at reduced risk of melanoma.