What teeth?...............
Posted on 05/23/2025 7:18:31 AM PDT by Red Badger
Vitamin D supplements may help prevent the loss of telomeres, DNA sequences that shrink with aging, a large study shows. But the health effects aren’t yet clear
Vitamin D supplements might slow cellular aging by preventing the loss of telomeres, DNA sequences at the ends of chromosomes that shorten in old age, a new study suggests. The health effects of these findings aren’t yet clear.
Vitamin D had been touted as a panacea for a number of health conditions, from cardiovascular disease to bone loss. In 2020 a large randomized controlled trial of supplementation instead found benefits only in a few conditions, particularly autoimmune disease and advanced cases of cancer, says the new study’s co-author JoAnn Manson, a professor of medicine at Harvard Medical School and a principal investigator of that large trial, called the VITamin D and OmegA-3 TriaL (VITAL). The new study is an analysis of data from VITAL. Its finding could explain the protective effect of vitamin D supplements on these specific aging-related diseases, Manson says.
“If is replicated in another randomized trial of vitamin D supplements, I think this could translate into clinical effects for chronic diseases of aging,” she says. “We’re already seeing that vitamin D does reduce inflammation; it reduces advanced cancers and cancer deaths, as well as autoimmune diseases. This could provide a biological mechanism.”
In the VITAL project, researchers enrolled nearly 26,000 women aged 55 or older and men aged 50 or older, and they randomly assigned participants to take vitamin D supplements, fish oil supplements, a combination of both or a placebo. For the new study, published today in the American Journal of Clinical Nutrition, the scientists looked at a subset of 1,054 participants who lived close enough to Harvard’s Clinical and Translational Science Center in Boston to have their blood drawn three times over four years so researchers could measure their telomeres.
Inside the nuclei of most cells in the human body reside 46 chromosomes, where our DNA is neatly packed. Each time a cell divides, these chromosomes unravel and copy themselves, and the copies coil back into the nuclei of the new cells. Telomeres are repetitive DNA sequences that cap the ends of chromosomes. They stabilize the chromosomes during cell division, though they get shorter each time cells divide. When the telomeres get very short, the cells stop dividing and die. Over time, as more and more of our cells die, the body ages and ultimately stops functioning. Telomeres aren’t a perfect clock for health—very long telomeres can increase cancer risk by stabilizing mutated cells—but they’re often used as a biomarker for aging.
Participants in the placebo and supplement groups had similar telomere lengths at the beginning of the study, the researchers found. But over the four years of follow-up, people assigned to take 2,000 international units of vitamin D per day showed less shortening of their telomeres compared with people in the placebo group. Fish oil had no significant effect.
“Vitamin D supplementation is able to slow down the telomere shortening process, at least during the four-year period,” says the study’s first author Haidong Zhu, a molecular geneticist at the Medical College of Georgia at Augusta University.
Participants started out with an average of 8,700 base pairs of DNA telomere length, and vitamin D supplementation slowed the loss of length by about 140 base pairs over four years, the study found.
The health implications of that number aren’t clear. “It’s only at the extremes that telomere length really matters in terms of aging,” cautions Mary Armanios, a professor of oncology and director of the Telomere Center at Johns Hopkins University, who was not involved in the research. The magnitude of difference seen in the vitamin D trial is within the normal range of human variation, meaning it may not equate with aging or youthfulness in any clinical sense.
“Most of us are going to be within this normal range, and there is a wide buffer for how much telomere length can change,” Armanios says.
In addition, Armanios says, the study used a method called quantitative polymerase chain reaction (qPCR) to assess telomere length, and this method can be very sensitive to factors such as when samples were collected and what time elapsed between collection and testing. “The methodology for telomere length measurement has been compared to others and found to be the least reproducible,” she says.
A large study of people aged 60 and older in the U.K. also found that very high levels of vitamin D in the blood were associate with shorter telomeres, suggesting that more is not always better. The participants in the VITAL study were supplemented with a moderate amount of vitamin D, Manson says.
Most of the participants in the new study were white, Zhu adds, so the results need to be replicated in a more diverse sample. The researchers are also currently analyzing data from the 1,054 VITAL participants to understand other facets of cellular aging, including DNA methylation, a type of regulation of gene expression.
The results are intriguing, says Anastassios Pittas, a professor of medicine at the Tufts University School of Medicine, who was not involved in the study. Vitamin D supplements are now recommended by the Endocrine Society for people aged 75 and older, as well as for people of any age with prediabetes to prevent the onset of type 2 diabetes, Pittas says. “These new findings from the VITAL study lend scientific support to these recommendations, highlighting possible mechanisms through which vitamin D may influence long-term health outcomes,” he says.
The findings are leading researchers toward a better understanding of who should pop a daily supplement, Manson says. “It shouldn’t be a universal recommendation to be screened for vitamin D blood levels or to take a supplement,” she says. “But it appears that selected high-risk groups may benefit.”
Ping!.........................
I take 5,000 IUs every day.
Doc put me on that for the month prior to hip replacement in 2020, and I felt great. Then Covid came, and D3 was recommended for prevention. So I never stopped taking it.
I’m still old though. My telomeres must be defective or something.
Interesting article, Red. What strikes me is the wildly contradictory data (U.S. vs U.K.), difficulty of measurement, and widely divergent opinions.
I’m 73 and spend some months in North Idaho where we don’t get a lot of sunlight and some months in the San Fran Bay Area were we get a lot more sun. I started taking 2,000 IU of Vitamin D per day as part of the COVID Protocols in March 2020.
After five years of Vitamin D, my telomeres are now so long that I can feel them tickling the insides of my cells.
>>>I take 5,000 IUs every day.<<<
Me too!...................
I’m 74 and take 12000 IU’s of D3 per day with vit, K2 which is recommended to take with D3.
I’ll drop my intake soon because of more exposure to the sun this spring and summer.
You might take vit K-2 in conjunction.
Best wishes.
Me three.
Democrats take 1,000,000 IUs of vitamin S daily.
*S(tupid)
Excess vitamin D reduces vitamin K and that damages teeth.
Vitamin k also sucks calcium out of your blood vessels and back into your bones (a good thing)
What teeth?...............
Some years ago my PCP tested blood and said my D was on low side of normal. So, take an OTC gel capsule . Did so. Six months later D concentration was high normal.
They cost practically nothing and cause no side effects at that dosage. Not testing for this is BS.
For some ODD REASON, Medicare doesn’t pay for Vitamin D Blood Testing..............hmmmmmmm.......................
There’s also that Israeli study from 2021 that showed that low Vit D increased COVID symptoms.
You might take vit K-2 in conjunction.
I know! I can’t believe these studies make no mention of the necessary K2 (abt 90-100 mcg/day) to go along with the recommended D3.
K2 it was keeps the calcium out of your arteries and *pushes* it into your bones, where you need it for strong bones.
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How to Safely Get Vitamin D From Sunlight
Good article. Very informative.
We take 4,000 iu of D3 daily as part of the Zelenko protocol. We haven’t had a sniffle since Nov 2022. I think that’s when we had covid which for us was a 3 day mild head cold and a lingering cough. We were never really sick. We never bothered to get tested.
If you are over 55 you should be on the Zelenko protocol. Our doctor can’t understand how we look, act and feel so much younger than our age.
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