A recent study suggests that daily vitamin D supplements could help preserve telomeres, the protective caps on chromosomes linked to aging. Researchers at Augusta University found that 2,000 IU doses maintained telomere length in older adults over four years. While promising, experts caution that optimal dosing remains unclear and lifestyle factors are essential for health.
Telomeres, the protective ends of chromosomes, shorten with each cell division, contributing to aging and diseases like cancer, heart disease, and osteoarthritis. Factors such as smoking, chronic stress, depression, and inflammation accelerate this process. Vitamin D, known for supporting bone health through calcium absorption and bolstering the immune system to reduce respiratory infections, also exhibits anti-inflammatory properties that may safeguard telomeres.
The study, part of the VITamin D and OmegA-3 TriaL (VITAL), involved 1,031 adults with an average age of 65. Conducted at Augusta University in the United States, participants were randomly assigned to receive either 2,000 IU of vitamin D daily or a placebo. Telomere lengths were measured at baseline, after two years, and after four years.
Results showed that the vitamin D group preserved telomeres by 140 base pairs compared to the placebo group. Telomeres naturally shorten by about 460 base pairs over ten years, making this preservation potentially significant. The findings, published in The American Journal of Clinical Nutrition in 2025, align with prior research linking anti-inflammatory diets, like the Mediterranean diet, to longer telomeres.
However, scientists emphasize uncertainties. Overly long telomeres might increase risks for certain diseases, and no consensus exists on ideal vitamin D dosages. Recommended daily intakes are 600 IU for adults under 70 and 800 IU for older adults, though some studies suggest 400 IU prevents infections. Optimal levels likely vary by individual factors, including current vitamin D status, diet, and nutrient interactions.
Researchers advise against viewing high-dose supplements as an anti-aging solution. Core habits—balanced diet, regular exercise, sufficient sleep, no smoking, and stress management—remain the strongest supports for telomere health. Supplementation is recommended for those deficient or at risk for bone issues, as further research explores vitamin D's role in aging.