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