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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

#61

Post by itsoktocry »

hannob wrote: 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.

Re: Reduced cancer mortality with daily Vitamin D intake

#62

Post by konschubert »

alejohausner wrote: post #54

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…

The statistics you are presenting - have they been corrected for life expectancy? Do they also hold across North America , eg comparing Florida to Boston?

Re: Reduced cancer mortality with daily Vitamin D intake

#63

Post by nomel »

Filligree wrote: post #12
CodeWriter23 wrote: post #10

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.

My takeaway is to keep eating fish.

Thanks to our polluted waters, there are pretty harsh limits to fish consumption [1] these days.

[1] https://www.hsph.harvard.edu/nutritionsource/fish/#:~:text=E....

Re: Reduced cancer mortality with daily Vitamin D intake

#64

Post by [deleted] »

itsoktocry wrote: post #61
hannob wrote: 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.

[deleted]

Re: Reduced cancer mortality with daily Vitamin D intake

#65

Post by ntonozzi »

frickinLasers wrote: post #35

It's maybe a good time to re-post this in-depth series on vitamin D supplementation. You don't want to take too much. https://www.devaboone.com/post/vitamin-d-part-2-shannon-s-st...

That article is so weird:

> Of course, there is a selection bias in who comes to me. There are people out there doing just fine on 5000 units of Vitamin D daily. I only see the ones who develop high calcium levels. But I see enough of them to know that this is not an exceptionally rare occurrence. I have been to lectures in which physicians have claimed that Vitamin D toxicity almost never occurs. In my experience, this is false. I have seen many cases of Vitamin D toxicity in people who were taking the recommended dose from an over-the-counter bottle.

She is an extremely specialized professional who is referred and treats people with this condition. Of course it's not rare in her experience! For all we know, she could be one of a hundred parathyroid specialists in the country, and only 1 in 100000 people who take Vitamin D get Vitamin D toxicity. The author should really provide some evidence on how common this is.

Re: Reduced cancer mortality with daily Vitamin D intake

#67

Post by subsubzero »

alejohausner wrote: post #54

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.

Re: Reduced cancer mortality with daily Vitamin D intake

#68

Post by mholm »

kelseyfrog wrote: post #7
mholm wrote: post #4

Earlier quoted context omitted.

That's what's confusing me: 105,000 participants in a study should have resulted in thousands of cancer deaths, a 12% drop should be pretty noticeable even with 10% of the data.

How exactly are you getting "should have resulted in thousands of cancer deaths"? A population of 100,000 should expect to see 144.1 deaths[1]. If you evenly divide the study group into two 52,500-sized groups(treatment + control), each group should expect to see 72 deaths. A 12% drop in one of the groups is 8.6 deaths. As a colleague would say, that's very few clams from which to make a chowder. Perhaps the research…

144.1 deaths per year. Presumably these studies lasted multiple years. Though I'll admit this was less than I expected, which would explain the differing results.

Re: Reduced cancer mortality with daily Vitamin D intake

#69

Post by bitL »

alejohausner wrote: post #54

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…

Taking D3 without K2 gives you atherosclerosis though so it's wise to combine the two.

Re: Reduced cancer mortality with daily Vitamin D intake

#70

Post by bitL »

hannob wrote: 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…

Simpson's paradox is well known - aggregate often has different statistical properties than individual parts.
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