Summary: New results from the VITAL randomized trial indicate that daily supplementation with vitamin D3 helps preserve telomere length in older adults, potentially slowing a key biological mechanism of aging. Telomeres are protective caps at the ends of chromosomes that progressively shorten with age and have been linked to higher risks of chronic disease.
Across four years, participants taking vitamin D3 showed significantly less telomere shortening than those taking a placebo—an effect the authors equate to nearly three years of delayed biological aging. These findings strengthen evidence that vitamin D3 could help reduce age-related cellular decline, although additional research is needed to determine long-term clinical benefits and mechanisms.
Key facts
- Slows telomere attrition: Daily vitamin D3 reduced telomere shortening over four years in the VITAL sub-study.
- Preserves cellular age: The magnitude of preservation corresponds to about three years of telomere health compared with placebo.
- No measurable benefit from marine omega-3s: Supplementation with marine n-3 fatty acids did not significantly affect telomere length in this analysis.
Source: Mass General
Overview
New data published in The American Journal of Clinical Nutrition come from a VITAL sub-study led by researchers at Mass General Brigham and the Medical College of Georgia. The randomized, double-blind, placebo-controlled trial assessed the effects of vitamin D3 and marine omega-3 fatty acid supplementation on leukocyte telomere length (LTL) over multiple years. Investigators report that vitamin D3 supplementation was associated with significantly smaller reductions in telomere length over four years, suggesting a protective effect on a molecular marker of aging.
“VITAL represents the first large-scale, long-term randomized trial to show that vitamin D supplements can help preserve telomere length,” said JoAnn Manson, MD, principal investigator of VITAL and chief of the Division of Preventive Medicine at Brigham and Women’s Hospital. Previous VITAL findings also linked vitamin D to reductions in inflammation and lower risks of selected chronic diseases of aging, including advanced cancer and certain autoimmune conditions.
Telomeres consist of repeating DNA sequences that cap chromosome ends, protecting them from degradation or fusion. Telomere shortening is a normal feature of aging and has been associated with increased risk for multiple age-related diseases. Prior small or short-term studies of vitamin D or omega-3 supplements produced mixed results, leaving a need for evidence from larger randomized trials.
VITAL enrolled U.S. adults—women aged 55 and older and men aged 50 and older—and employed a 2 x 2 factorial design to test daily vitamin D3 (2,000 IU) and marine omega-3s (1 g). The telomere sub-study included 1,054 participants whose leukocyte telomere length was measured at baseline, Year 2, and Year 4.
The analysis showed that vitamin D3 supplementation significantly reduced telomere attrition over four years compared with placebo, corresponding to an average reduction of 0.14 kilobase pairs (kb) in telomere loss. In trend analysis, the vitamin D3 group had LTLs about 0.035 kb higher per year of follow-up than the placebo group. In contrast, marine n-3 fatty acids produced no significant effect on telomere length at either Year 2 or Year 4.
“These results suggest that targeted vitamin D3 supplementation may be a promising approach to slow a cellular aging pathway,” said Haidong Zhu, PhD, first author and molecular geneticist at the Medical College of Georgia. The authors note that while the observed telomere preservation is encouraging, further research is necessary to establish long-term health outcomes and to better understand underlying biological mechanisms.
Authorship and disclosures
The VITAL telomere report lists JoAnn Manson and additional Mass General Brigham authors including Nancy R. Cook, William Christen, and I-Min Lee. Other contributors include Haidong Zhu, Bayu B. Bekele, Li Chen, Kevin J. Kane, Ying Huang, Wenju Li, and Yanbin Dong. The authors report no known competing financial interests or personal relationships that influenced the work.
Funding
This research was supported by the National Heart, Lung and Blood Institute (R01 HL131674-01). The parent VITAL trial receives support from R01 AT011729. Funders did not participate in study design, data collection, analysis, interpretation, writing of the report, or the decision to submit the manuscript for publication.
About this aging research news
Author: Alexandra Pantano
Source: Mass General
Contact: Alexandra Pantano – Mass General
Image: Image credit: Neuroscience News
Original research (open access):
“Vitamin D3 and Marine Omega-3 Fatty Acids Supplementation and Leukocyte Telomere Length: 4-Year Findings from the VITAL Randomized Controlled Trial” by JoAnn Manson et al., American Journal of Clinical Nutrition.
Abstract
Vitamin D3 and Marine Omega-3 Fatty Acids Supplementation and Leukocyte Telomere Length: 4-Year Findings from the VITAL Randomized Controlled Trial
Background
Existing small studies have hinted that vitamin D or omega-3 fatty acid supplementation may support telomere maintenance, but robust randomized clinical trial evidence has been lacking. Using data from the VITAL trial, researchers tested whether daily vitamin D3 or marine n-3 fatty acids reduce leukocyte telomere length (LTL) attrition over time.
Methods
VITAL is a large, randomized, double-blind, placebo-controlled trial with a 2 x 2 factorial design evaluating vitamin D3 (2,000 IU/day) and marine n-3 fatty acids (1 g/day) over five years in a representative cohort of 25,871 U.S. adults (women ≥55 years; men ≥50 years). The VITAL Telomere sub-study (NCT04386577) included 1,054 participants evaluated at the Harvard Clinical and Translational Science Center. LTL was measured by absolute telomere length qPCR at baseline, Year 2, and Year 4. Primary outcomes examined changes in LTL over time using mixed-effects linear regression models.
Results
LTL measurements were obtained from 2,571 samples across 1,031 participants at baseline, Year 2, and Year 4. Compared with placebo, vitamin D3 supplementation significantly reduced LTL attrition by 0.14 kb (95% CI: 0.01–0.27) over four years (p = 0.039). Trend analysis indicated the vitamin D3 group maintained approximately 0.035 kb more telomere length per year of follow-up than placebo (p = 0.037). Marine n-3 fatty acids showed no significant effect on LTL at either time point.
Conclusion
Four years of daily vitamin D3 supplementation (2,000 IU/day) reduced telomere attrition by about 140 base pairs, suggesting that vitamin D3, with or without marine n-3 fatty acids, may help slow telomere erosion and cellular senescence. Further research is needed to determine clinical implications and to confirm these findings over longer follow-up periods.