https://www.jpost.com/health-and-wellness/health-and-wellness-around-the-world/article-855305 Participants taking 2,000 IU of vitamin D daily had significantly less telomere loss over four years, study finds. A new study published in The American Journal of Clinical Nutrition revealed that vitamin D supplementation may slow biological aging by preserving the length of telomeres, the protective caps at the ends of chromosomes. Researchers in the VITAL Telomere study found that participants taking 2,000 International Units (IU) of vitamin D3 daily experienced less telomere shortening over four years compared to those who received a placebo. The VITAL Telomere study is a sub-study of the larger VITAL trial, a randomized, placebo-controlled, and double-blind trial involving nearly 26,000 participants in the United States, including women aged 55 and older and men aged 50 and older, tracked for five years. In the sub-study, 1,054 adults participated, and the length of telomeres in their white blood cells was assessed at baseline, after two years, and after four years. Telomeres are made of repetitive sequences of DNA, or base pairs, which prevent chromosome ends from degrading or fusing with other chromosomes. They serve as protective structures that prevent genetic material from being damaged during cell division. With each cell division, telomeres become slightly shorter, a natural part of aging. Shortened telomeres are linked to chronic diseases such as type 2 diabetes and cardiovascular diseases. "VITAL is the first large-scale and long-term randomized trial to show that vitamin D supplements protect telomeres and preserve telomere length. This is of particular interest because VITAL had also shown benefits of vitamin D in reducing inflammation and lowering risks of selected chronic diseases of aging, such as advanced cancer and autoimmune disease," stated JoAnn Manson, principal investigator of the VITAL trial and a professor at Harvard Medical School, according to a report by The Independent. Participants in the study were randomly assigned to receive vitamin D3 (2,000 IU/day), omega-3 fatty acid supplements (1 g/day), a combination of both, or a placebo. The researchers found that those who received vitamin D3 supplements showed a slower rate of telomere shortening over the four-year period compared to those who received a placebo. After four years, the decrease in telomere length was about 7% in the vitamin D group, while in the placebo group, it reached 28%, corresponding to an aging advantage of almost three years for the vitamin D group. "Our findings suggest that targeted vitamin D supplementation may be a promising strategy to counter a biological aging process, although further research is warranted," said Haidong Zhu, first author of the report and a molecular geneticist at the Medical College of Georgia, Augusta University, according to a report by Newsweek. The study also found that omega-3 fatty acid supplementation had no effect on telomere length during the follow-up period. Participants taking omega-3 supplements did not show a relevant impact on telomere length compared to those taking a placebo.
My question is, what is the magic behind 2,000 IU/day? Why not 1,000 IU? Why not 3,000 IU? I ask because my multivitamin has 800 IU. Is that close enough? Does it fall far short? Going forward, I think it would be useful to conduct a sensitivity analysis to determine the sweet spot.
I know a lady who has problems assimilating vitamin D. Sometimes she does, sometimes not. Doesn't depend on anything she can figure out and it is driving her nuts. And it doesn't matter how much she takes, or how much time she spends in the sun. She is constantly getting tested. I guess if your levels kept getting really low you would be OCD on the matter also.
AI says 2000 IU would be safe and more effective than 1000 IU (but remember AI might have an incentive to exterminate humans). https://www.perplexity.ai/search/why-did-the-vital-telomere-stu-iJP46VtwT5eMZZVqsSGd8g
And now, for some rain on the parade: Vitamin D Probably Can’t Slow Aging https://gidmk.medium.com/vitamin-d-probably-cant-slow-aging-1a7f9e927df2 How endless headlines are coming from the same tired dataset. Vitamin D is probably the most written-about supplement of all time. It’s essential for all sorts of bodily systems, and decades of research have shown that having lower levels of the vitamin put you at higher risk of everything from heart disease to dementia. It’s also very safe, cheap to produce, and therefore a very promising target for intervention. To put it simply: people who have less vitamin D are generally much less healthy than those with more. Surely that means taking a supplement is good for your health? The problem with this idea is that we have been researching vitamin D supplements for a very long time, in some of the biggest randomized trials ever conducted. Overwhelmingly, we have seen no benefits from taking the pills. Which makes the recent headlines about the supplement a bit confusing. According to global media, you can slow your aging by taking vitamin D. If true, this would finally justify the billions of dollars spent each year on the massive global market for the pills. Unfortunately, the science doesn’t hold up to scrutiny. There’s no reason to believe that you can slow your aging processes by taking a vitamin D supplement just yet. The Study The new vitamin D paper is a subgroup analysis of a previous randomized trial. The VITAL study was a huge effort that randomized 25,000 people in a 2x2 design to either get vitamin D, fish oil, both, or a placebo that started in 2010 and finished in 2018. The results came out in 2019 — no benefits for either vitamin D or fish oil supplements on any of the main primary endpoints like heart disease, serious illness, or death. However, giant trials like this have vast quantities of data. You don’t just publish one study from such a huge body of work — there’s more science to be done! The newest offering looks at a subset of 1,000 people who were randomized as part of the VITAL study at Harvard and who had testing of their telomere length. Telomeres are one of the main targets for aging research. They are repetitive sections of DNA at the end of chromosomes, and they get shorter as we age. No on is entirely sure why this happens, but it seems to be related to the bad things that are associated with aging like chronic disease and frailty. Longer telomeres are generally thought to be better than shorter ones, although it’s unclear if simply lengthening telomeres confers health advantages or if the relationship is more complex than that. In this sub-study, the authors looked at telomere length in the vitamin D and fish oil groups compared to their respective placebos. The fish oil showed no benefits but there was a very minor benefit associated with taking vitamin D supplements. Specifically, over the course of 4 years, people taking vitamin D had telomeres that were on average 140 base pairs longer than those not taking the pills, with a p-value of 0.039. For some context, human telomeres are around 15,000 base pairs long. 4 years of life would itself be correlated with losing 120–400 base pairs, meaning that this is not even keeping up with the general process of aging. While it is a difference, and it’s clearly big enough to make headlines, the actual meaning that this difference has is very questionable. Remember, the main results of the study did not show any benefits for everything from heart attacks to death! Bottom Line There’s a very telling sentence in the paper which basically shows how pointless this all is: When you’re interpreting scientific research, one of the big issues is researcher degrees of freedom. If you run enough statistical tests, the chances that you’ll come up with an answer that supports a particular point of view — say, that vitamin D supplements are beneficial — starts to get close to 100%. To combat this, we require people who are doing randomized clinical trials to pre-register not just their study design but also the analyses that they are planning on doing on that data. This study was not pre-registered. The authors posted a public registration document more than three years after the VITAL study had already finished. The data had been collected, analyzed, and as the phrase goes, tortured quite a bit, before this paper was even conceived. We don’t know how many other analyses the authors ran. We don’t know how many pieces of data that they collected and left out. We’ve got no idea which other models or subgroups might show a different result for telomere length when compared to people who were recruited from Harvard for this study. There are many ways to deal with this, but one of the most common is simply to correct for the issue statistically. You can adjust your statistical analyses to see if the results that you’ve found are truly significant numerically, or if they are more in line with what we’d expect to see even if the supplements had no benefit. The quote above basically says that the authors didn’t do this. Why? Well, they don’t really say, but the fact that the p-value of their primary analysis is 0.039 points towards the obvious answer — any correction for multiple comparisons would render these results meaningless. The traditional threshold for statistical significance is 0.05, and even the most basic modifications to 0.039 would push it over that. If the authors had done the most common adjustment for their stats, they’d be left with a study where vitamin D pills probably didn’t do anything for telomere length. Ultimately, this new paper reads very similar to the rest of the vitamin D research. VITAL showed no benefits for the things we care about — like dying — and even the subgroup benefits like telomere length are highly questionable. At best, this paper shows that taking vitamin D pills for years of your life may have a tiny benefit that is not strongly related to long-term improvements in your health. We know that vitamin D supplements probably don’t do much — if anything — for people’s health. This has been true in dozens of massive randomized trials, including everyone from people in low-sunlight areas, those with low vitamin D levels, and more. The newest paper simply shows that even when you torture the data into weird shapes, it still shows at best tiny benefits that may be caused by taking vitamin D pills.
I would say way too small. Generally multivitamins are good to keep you just on the very low end of needed. But specially with vitamin D, because theoretically it can be overdosed, they are way more conservative. People low on D get 50K pills. One of the YTer supplement guy advocates 5K daily. For comparison, in the summer time 30 minutes in the Sun you can get 20K equivalent of D dose. So if the Sun can't overdose humans, the pills shouldn't be able either. Relevant part is after 5 minutes.