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Reduced cancer mortality with daily Vitamin D intake

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Re: Reduced cancer mortality with daily Vitamin D intake

#91
post #85

It took me a long time, and virtually no help from outside, to discover that vitamin D effectively cures my winter depression. I was never really feeling good around that time of the year, but it wasn't problematic enough to actually do something about it. But when my gut started to revolt around that time too, I started to feel distinctly unwell. So I went to my doctor, who gave me an approintment with a nutrition s…

I had a similar experience. It was night and day too.

Re: Reduced cancer mortality with daily Vitamin D intake

#92

Earlier quoted context omitted.

I have some hard numbers on this in my own health. I'm a pasty north European living in California and I get plenty of sunshine, as I enjoy the outdoors. As I got older, I got increasingly more viral infections and strep throat was a twice a year affair. It didn't occur to me that I could be vitamin-D deficient, but I was, severely. For some reason, 10+ hours of sunshine a week isn't enough for me to make my own. Ove…

Just because you get plenty of sunlight where you live it doesn’t mean you get enough exposure to produce vitamin D. You need to expose large areas of your body like legs, arms, and torso for several minutes to an hour. If those areas are covered, sunlight won’t do much. The Sigma Nutrition podcast has an excellent episode on that: https://sigmanutrition.com/episode438/

Nah, for me, that wasn't sufficient. I get at least 10 hours a week of full sun on my whole arms and legs and sometimes my torso if I decide to bike shirtless; more sun than most people, and still, I was vitamin D deficient.

Re: Reduced cancer mortality with daily Vitamin D intake

#93
post #2

"When all 14 studies were pooled, no statistically significant results emerged. However, when the studies were divided according to whether vitamin D3 was taken daily in a low dose* or in higher doses administered at longer intervals*, a large difference was seen." This sounds fishy. Sounds like their primary result was nothing, and then they looked for something else. Would require some checking if they had a prereg…

> Would require some checking if they had a preregistration, if this was registered as a secondary resuld and if they had done a proper statistica analysis of multiple outocmes. You should do that. Meanwhile, I'm going to (continue to) take a daily vitamin D, because I recognize not everything can be confirmed by a double-blind experiment, and the cost is low.

> "I'm going to (continue to) take a daily vitamin D, because I recognize not everything can be confirmed by a double-blind experiment, and the cost is low."

Or it may be possible to prove the opposite, as with the parachute.

bmj: "Parachute use to prevent death and major trauma when jumping from aircraft: randomized controlled trial"

https://www.bmj.com/content/363/bmj.k5094

Results: Parachute use did not significantly reduce death or major injury (0% for parachute v 0% for control; P>0.9). This finding was consistent across multiple subgroups. Compared with individuals screened but not enrolled, participants included in the study were on aircraft at significantly lower altitude (mean of 0.6 m for participants v mean of 9146 m for non-participants; P

"Conclusions: Parachute use did not reduce death or major traumatic injury when jumping from aircraft in the first randomized evaluation of this intervention. However, the trial was only able to enroll participants on small stationary aircraft on the ground, suggesting cautious extrapolation to high altitude jumps. When beliefs regarding the effectiveness of an intervention exist in the community, randomized trials might selectively enroll individuals with a lower perceived likelihood of benefit, thus diminishing the applicability of the results to clinical practice."

disclaimer:

I am pro-Parachute! I believe 100% in the effectiveness of the parachute!

Re: Reduced cancer mortality with daily Vitamin D intake

#94
post #85

It took me a long time, and virtually no help from outside, to discover that vitamin D effectively cures my winter depression. I was never really feeling good around that time of the year, but it wasn't problematic enough to actually do something about it. But when my gut started to revolt around that time too, I started to feel distinctly unwell. So I went to my doctor, who gave me an approintment with a nutrition s…

> Why I type this here? I found it interesting that I had to discover this cure on my own. The medical system wuldn't have figured that out on their own, let alone accept that it was the single solution.

It's because studies showing correlation between Vitamin D level and winter depression/SAD are mixed.

I'm not saying it's a placebo. If it works for some people - great! But you can't expect doctors to recommend it when the data is quite unclear.

Re: Reduced cancer mortality with daily Vitamin D intake

#95
post #58

Earlier quoted context omitted.

D3 (animal-based) > D2 (plant-based) > D1 (synthetic), at least in humans if you read the literature, that is. The fishy thing is how actual scientists do whole studies using only D1 and then draw conclusions.

Plant-based D3 exists, extracted from seaweed.

Vegan D3 can also be derived from lichen; here's one such product:

https://www.futurekind.com/products/vegan-vitamin-d3

Re: Reduced cancer mortality with daily Vitamin D intake

#96

Earlier quoted context omitted.

>> This sounds fishy. Sounds like their primary result was nothing If you combine results from a bunch of studies that really didn't do anything, it's going to mask the results from the ones that did.

Maybe, but with 14 studies you have ~2^14 ways to split the studies into two groups. If you test multiple hypotheses, you have too adjust the p-value accordingly. Have the authors disclosed how many alternative hypotheses were tested until the result in the article was found to be significant?

P-values don't prove anything about whether an effect is real or not. They, at most, provide some degree of confidence with the presumption that the independent and dependent variables are indeed independent and dependent.

P-values should, at most, be used to direct further mechanistic studies (if possible). Only use them on their lonesome if this hasn't yet been done, or isn't possible. And if that's the case, reverify them independently (such as by doing another meta-analysis using different data).

Re: Reduced cancer mortality with daily Vitamin D intake

#97
post #94
post #85

It took me a long time, and virtually no help from outside, to discover that vitamin D effectively cures my winter depression. I was never really feeling good around that time of the year, but it wasn't problematic enough to actually do something about it. But when my gut started to revolt around that time too, I started to feel distinctly unwell. So I went to my doctor, who gave me an approintment with a nutrition s…

> Why I type this here? I found it interesting that I had to discover this cure on my own. The medical system wuldn't have figured that out on their own, let alone accept that it was the single solution. It's because studies showing correlation between Vitamin D level and winter depression/SAD are mixed. I'm not saying it's a placebo. If it works for some people - great! But you can't expect doctors to recommend it w…

I am a high risk cancer patient who is blind, i.e. doesn't necessarily get a lot of sun exposure due to disability + occupation. Given the discussion in this thread regarding correlation with lattitude and cancer risk, me being around 47 deg, and my personal history, I would have expected a caring medical system to suggest vitamin D to me roughly 30 years ago already. But alas, it turns out you have to do your own studies to improve life expectency with our western medical system. I could tell you a lot more, regarding being abused as a subject for a medical experiment at the age of 7! But people like you will always step up and defend the system. Observe and learn, I say.

Re: Reduced cancer mortality with daily Vitamin D intake

#98

The global distribution of many types of cancer is strongly related to latitude. The farther you are from the equator, the higher the rate of disease. The more sun you get, the less cancer. It's hard not to infer that sun exposure and thus synthesis of vitamin D helps prevent many cancers. We've been urged to avoid sun exposure because it can cause skin cancer. But those cancers are squamous and basal cell carcinomas…

As someone who spends alot of time outside(as much as I can while still working!) and also takes 5000iu of vitamin D, I just wanted to say there is moderation in everything. Getting too much sun can lead to skin cancer so make sure you are wearing sunscreen.

I worked on a project related to modelling UV and skin cancer rates. And what I learnt there is that that big thing that causes skin cancer isn't so much total UV exposure over a year, but a sudden switch for long periods of no sun to a period of intense sun. You see this especially in the Nordic countries where it isn't uncommon to go from 4 month of getting essentially no sun to 10 days of spending 10 hours a day in a bathing suit on a beach in Thailand or Bali.

Re: Reduced cancer mortality with daily Vitamin D intake

#99
post #85

It took me a long time, and virtually no help from outside, to discover that vitamin D effectively cures my winter depression. I was never really feeling good around that time of the year, but it wasn't problematic enough to actually do something about it. But when my gut started to revolt around that time too, I started to feel distinctly unwell. So I went to my doctor, who gave me an approintment with a nutrition s…

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