A simple tablet swallowed every morning could save the equivalent of three years on the biological clock of our cells, according to American researchers. For four years, they monitored the length of telomeres, these “caps” which protect our chromosomes and whose shortening accompanies aging. In their clinical study, a common supplement managed to slow down this erosion, where the placebo allowed telomeres to shorten significantly.
This is the daily supplementation of
vitamin D3 at 2,000 IU, or 50 micrograms, tested in the VITAL trial in adults over 50 years old.
A sub-study involving just over 1,000 participants shows that this dosage limits the shortening of white blood cell telomeres compared to placebo, which would correspond, according to the authors, to approximately three years of biological aging in less.
Vitamin D and telomeres: what the VITAL trial reveals
THE telomeres are short DNA sequences located at the ends of chromosomes and they protect them. With each cell division, they shorten. “When telomeres become too short, cells enter senescence (a state where they no longer divide) or apoptosis (programmed cell death). In both cases, this arrest or death of cells is considered to contribute to aging and age-related diseases“explained David Cutler, MD, to Medical News Today.
In the VITAL trial, participants received 2,000 IU of vitamin D per day, or a placebo, sometimes with omega-3. For the sub-study, a little more than 1,000 volunteers monitored at Harvard gave blood samples at the beginning, after two years and then four years.
The researchers measured the telomeres of white blood cells: the vitamin D group showed minimal shortening, while the placebo and omega-3 alone were accompanied by a clear shortening.
A promise for biological aging, but clear limits
The researchers note a clearer effect of vitamin D in certain subgroups, notably among non-white participants, but they urge caution and describe these analyzes as “hypothesis-generating”. They also point out that this study on telomeres is post-hoc, mainly concerns white subjects over 50 years old and that approximately 37% of the data was missing at four years, which limits the solidity of the conclusions.
The doctor Yoshua Quinones, author, interviewed by “Medical News Today”, sees this as a possible advance for preventive medicine and believes that, if these results are confirmed, daily supplements of vitamin D could one day reduce the risk of age-related diseases. The researchers emphasize, however, that these benefits remain to be confirmed by clinical trials and by work on telomerase and DNA protection.
Vitamin D supplements: what dose and for whom?
Authorities generally recommend 800 IU (20 micrograms) per day, and David Cutler points out that excessive doses can cause kidney toxicity.