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.
Telomere shortening is a natural part of aging, but when telomeres become very short, cells stop dividing and die. This shortening is linked to an increased risk of infections, type 2 diabetes, cardiovascular diseases, and decreased organ function.
"It's only at the extremes that telomere length really matters in terms of aging," cautioned Mary Armanios, a professor of oncology and director of the Telomere Center at Johns Hopkins University, according to a report by Scientific American. She noted that most people have telomeres within a normal range, and there is a wide buffer for how much telomere length can change.
While vitamin D supplementation shows promise in slowing biological aging processes, experts advise that it is not a cure-all and should not replace a healthy diet and lifestyle. "Dietary supplements will never be a substitute for healthy diet and healthy lifestyle, and we've made it very clear time and again that the focus should be on the diet and lifestyle rather than on supplementation," stated Manson, according to a report by The Washington Post. She added that targeted supplementation for people who have higher levels of inflammation or a higher risk of chronic diseases may be beneficial.
Vitamin D, also known as "the sunshine vitamin," is essential for immune system function, calcium absorption in the intestine, and bone health. It supports immune function, regulates inflammation, influences cell growth, and fulfills many other functions. Despite its benefits, the most natural way to obtain vitamin D is through exposure to sunlight, but lifestyle, geography, or sunscreen use can limit exposure.
The preparation of this article relied on a news-analysis system.
