24/08/2025
A new study suggests that Vitamin D supplements may help preserve telomeres external link —the DNA caps at the ends of chromosomes that maintain genetic stability and protect against cell death. If the findings can be replicated, researchers say, they could point to a “promising strategy” for countering biological aging.
Telomeres, which are themselves made of DNA, shorten every time a cell divides; this shortening has been linked to aging and to age-related diseases like vascular dementia, type II diabetes, and cancer.
To find out whether Vitamin D supplements can slow this process, scientists examined the white blood cells of more than 900 people enrolled in the VITamin D and OmegA-3 TriaL (VITAL) trial, a randomized controlled trial of Vitamin D and omega-3 supplementation in nearly 26,000 men and women over five years. Roughly half the participants took 2000 IUs of Vitamin D3 per day; the other half took a placebo.
When researchers compared telomere length in white blood cells between the two groups, they found a significant difference: Telomeres in the Vitamin D group were longer over time, losing 140 fewer base pairs of DNA on average over four years. (Participants started with an average of 8700 base pairs.) Based on previous studies, that could equal up to three years of aging, the researchers say.
The research was supported by NHLBI and published in The American Journal of Clinical Nutrition.
