I have been hesitating to present these, but I was about
to present them in a different thread, and was unable to do so. I anticipate some negative responses, but hopefully all will remain friendly and free of insults and any ad hominem approach. I actually have become quite bored/tired with the endless battle over supplementation or even diet, and would rather wait until a really strong and hopefully unbiased study comes along, whether for or against, whatever. But I feel like I already(in previous thread) needed to get these in there for consideration, so I am going to post them.
I have not been able to dig into the details yet, but I am pretty sure that at least many or most of these studies have still just been observing the relatively small, "approved" doses of 400-800 IU per day, no where near the doses some of our docs have some of us on, or nothing like the 4000IU/day discussed in a previous thread, but I'm not certain yet. I also do not know if PC was represented in the cancer mortality, but there have been recent claims that vitamin d3 supplementation is not helpful for anything whatsoever, so this might be a counter to that claim. Or not. For our experts in research who might claim there is no evidence here, keep in mind that those conducting these meta-analyses are at least as expert as anyone here, so their conclusions might be worth reading. So, here you go in case you are interested:
cochranelibrary-wiley.com/doi/10.1002/14651858.CD007470.pub3/abstract;jsessionid=A25F9BC9DB2408AD52F342EB164FB564.f01t02Somebody said...
Selection criteria
Randomised trials that compared any type of vitamin D in any dose with any duration and route of administration versus placebo or no intervention in adult participants...........Accordingly, 56 randomised trials with 95,286 participants provided usable data on mortality......Vitamin D was administered for a weighted mean of 4.4 years......When different forms of vitamin D were assessed in separate analyses, only vitamin D3 decreased mortality... RR 0.94... Vitamin D2, alfacalcidol and calcitriol did not significantly affect mortality....Vitamin D3 statistically significantly decreased cancer mortality (RR 0.88).... Vitamin D3 combined with calcium increased the risk of nephrolithiasis (RR 1.17)...... Vitamin D3 also seemed to decrease cancer mortality...In conclusion, we found some evidence that vitamin D3 seems to decrease mortality... in elderly people living independently or in institutional care. ....More randomised clinical trials are needed on the effects of vitamin D3 on mortality...further placebo-controlled randomised trials seem warranted.
/www.bmj.com/content/348/bmj.g1903Somebody said...
Study selection Observational cohort studies and randomised controlled trials in adults, which reported associations between vitamin D (measured as circulating 25-hydroxyvitamin D concentration or vitamin D supplement given singly) and cause specific mortality outcomes.
Data extraction Data were extracted by two independent investigators, and a consensus was reached with involvement of a third. Study specific relative risks from 73 cohort studies (849 412 participants) and 22 randomised controlled trials (vitamin D given alone versus placebo or no treatment; 30 716 participants) were meta-analysed......Results In the primary prevention observational studies, comparing bottom versus top thirds of baseline circulating 25-hydroxyvitamin D distribution, pooled relative risks were 1.35 .. for death from cardiovascular disease, 1.14 for death from cancer, 1.30 (1.07 to 1.59) for non-vascular, non-cancer death, and 1.35 (1.22 to 1.49) for all cause mortality. Subgroup analyses in the observational studies indicated that risk of mortality was significantly higher in studies with lower baseline use of vitamin D supplements. In randomised controlled trials, relative risks for all cause mortality were 0.89 (0.80 to 0.99) for vitamin D3 supplementation....
Conclusions Evidence from observational studies indicates inverse associations of circulating 25-hydroxyvitamin D with risks of death due to cardiovascular disease, cancer, and other causes. Supplementation with vitamin D3 significantly reduces overall mortality among older adults;
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Discussion:....However, when stratified by type of supplementation, vitamin D3, given singly, reduced all cause mortality significantly by 11%. By contrast, supplementation with vitamin D2 alone had no overall effect on mortality....