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Comment · 1 year ago
The proper claim is that raising people from deficient (<20ng/ml) to a sufficient level (>30ng/ml ideally) should improve outcomes. Sometimes looking at a subset of those who started deficient is good enough to find such an effect, but sometimes it isn't, such as if the dose used was not high enough to raise people up enough, particularly common if the subjects weights were high which requires higher intakes to move the needle a lot, so other subset analysis look at norm-weight subjects. Proper study guidelines were published in the mid 2010s and meta-analyses like this one that aggregate many studies that don't conform to these guidelines are just as invalid as individual studies that don't.

For detailed treatment of this see this thread on X: https://x.com/KarlPfleger/status/1732514710715514883

Comment · 1 year ago
Nonesense. It's well established that dietary D3 (or D2, but D3 is better) clearly incleases 25(OH)D serum levels. It is that serum biomarker whose deficiency (levels below 20ng/ml or 30ng/ml) that has the largest association with higher risk of dozens of diseases as well as all-cause mortality. You can defend your phrasing by saying that "not well" just means one has to take a lot of it. Yes, there is a wide variety of dose response, which is why it's best to test blood levels to titrate supplementation amount.
Comment · 1 year ago
The academic paper this story is based on is here: https://nature.com/articles/s43587-024-00793-y Despite the linked story title only mentioning omega3, the paper was about 3 interventions, that, vitamin D, exercise and found reduced epigenetic age from the interventionts, with bigger anti-aging benefit as they were combined.

With respect to vitamin D specifically, this isn't by itself good evidence vitamin D reverses aging. But it is consistent with the totality of evidence that being vitamin D deficient probably (causally) speeds aging. And it mildly increases the overall weight of evidence of a connection.

As with much vitamin D research, it would have been better for the intervention to have been titrate vitamin D supplement amount to achieve an optimal target range (eg 30-60ng/ml) rather than using a fixed relative moderate dose (2000IU).

The problem with a fixed dose is that surely some subjects started severely deficient, some mildly, and some had sufficient levels. The moderate but not very high fixed dose will have helped many in the middle group climb out of deficiency, not been enough for many in the 1st group to bring them fully out of deficiency, and been unnecessary for those in the 3rd group, so the study ends up seeing a weaker overall effect averaged over all subjects. This is well known within the vitamin D world, eg see https://x.com/KarlPfleger/status/1732514710715514883, but somehow has not permeated to be widely enough understood, even within the scientific community (or the Hacker News community).

For an extensive list of papers supporting a link between vitamin D and speed of aging, see https://x.com/KarlPfleger/status/1390717755158974464

Comment · 1 year ago
For more extensive discussion see my X thread here: https://x.com/KarlPfleger/status/1888649974621347950
Comment · 1 year ago
No, ample evidence shows that vitamin D (or vitamin D deficiency at least) is causally related to multiple diseases. The evidence is pretty overwhelming. Eg here's a just published review on D deficiency causality for Covid based on applying Hill's Criteria for causality https://www.mdpi.com/2072-6643/17/3/599 and a prior 2022 paper on the same subject https://pubmed.ncbi.nlm.nih.gov/35308241/

Some vitamin D skeptics claim tat there's insufficient evidence from RCTs but few people question the causality of smoking's influence on cancer despite no RCTs for that---that relationship was established also via Hill's Criteria.

Comment · 4 years ago
I put extended analysis of the results & caveats of what it means (correlation vs causation, etc.) on Twitter: https://twitter.com/KarlPfleger/status/1557814485070409728
Comment · 4 years ago
I've collected the results from all 4 papers including the links to all 4 in a Google spreadsheet for easily lining up the results for each stage of Covid: https://docs.google.com/spreadsheets/d/1a5twV0x-TlHzd2AVr9e1... 1 tab for the links & underlying number of studies/patients & 1 tab for the results.
Comment · 4 years ago
4 big systematic meta-analyses since Dec'21. Consistent results from all 4: Low D levels or not supplementing D has 1.5x-3x worse Covid risk at all stages (infection to mortality).
Comment · 4 years ago
Some critical responses to this new study are starting to accumulate: Dr. Peter Attia's takedown: https://peterattiamd.com/vitamin-d-nejm-study/ Dr. Ronald Hoffman: https://drhoffman.com/article/whats-up-with-that-vitamin-d-s... Council for Responsible Nutrition: https://www.nutraingredients-usa.com/Article/2022/07/29/crn-... And a 3-part series from non-profit GrassrootsHealth (only 2 parts so far that I see): part 1: https://www.grassrootshealth.net/blog/go-part-1-3-headlines-... part 2: https://www.grassrootshealth.net/blog/go-part-2-3-vital-anal...
Comment · 4 years ago
One reason getting these from the evolved route may be better is because feedback mechanisms stop making the beneficial substance when the body has enough, which may not happen via intake by other methods. This is the case for vitamin D from sun vs oral D supplements. Serum levels stop going up when they reach a natural adequate evolutionary range if it's coming from sun. I don't know if that's true of NO or not. Or of melatonin from the near-infra-red wavelengths, but I wouldn't be surprised.
Comment · 4 years ago
I thought this piece spent too much time arguing about the wrong things (such as evolutionary stuff). I added 3 comments on what I think are the most important points with links to scientific research to the comments on Apr 22. Just search for Pfleger using find-in-page to read them.
Comment · 5 years ago
Just how much lower it would get cannot be discerned from available data yet. It is very hard to believe from current data that it would go all the way to zero and also very hard to believe that fixing all vitamin D deficiency would not save any lives. The confidence interval range in between is still large, but it is absolutely (past) time to act on the data because it is so unlikely to not help (or even not help a lot). And the data is so far consistent with the possibility that it could help so much that it would have reduced the pandemic to no worse than prior flu seasons had everyone's vitamin D been brought up above 30ng/ml before SARS-CoV-2 arrived.
Comment · 5 years ago
Did you read the open letter (original link of thread)? There is an entire paragraph and footnote with 2 refs talking about the problem with the current government guidelines.
Comment · 5 years ago
The site itself was set up (by me) just to host this open letter, just as the site masks4all.co was set up to host the similar open letter that happened for masks in the spring. The credibility isn't of the site itself but of the signatories of the site, which are listed plainly (with any conflicts of interest). Look through the list yourself to judge their credibility.

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