Dr. Madhur Verma and Dr Sanjay Kalra
Vitamin D supplementation may help maintain telomere length, which is crucial for healthy aging, according to 4-year results from the VITAL trial published in The American Journal of Clinical Nutrition.1
This study examined whether daily supplementation of vitamin D3 (2000 IU/day) or marine omega-3 fatty acid (n-3 FA; 1 g/day) could reduce shortening of leukocyte telomere over a period of 4 years, using data from the VITamin D and OmegA-3 TriaL (VITAL) trial.
The VITAL trial was a large, randomized, double-blind, placebo-controlled trial involving 25,871 adults aged ≥55 for women and ≥50 for men in the US, which examined the impact of 5-year supplementation of vitamin D (2000 IU/day) and omega-3 fatty acids (1 g/day) in the primary prevention of cancer and CVD. The 1054 participants of the VITAL Telomere study, an ancillary study of the VITAL trial, were also included.
A total of 2571 LTL measurements, from the 1031 participants, at the start of the study, at 2 years and at 4 years using a quantitative polymerase chain reaction method, were included in the present study. Changes in telomere length in leukocytes between baseline and the two assessment points were the primary outcome measures.
Results showed that vitamin D3 supplementation significantly reduced LTL attrition by 0.14 kilobase pairs (kb) over 4 years compared to placebo. Analysis further indicated that LTLs were approximately 0.035 kb longer per year in the vitamin D3 supplemented group than the placebo group preventing the equivalent of nearly three years of aging. Conversely, marine n-3 fatty acid supplementation had no significant effect on telomere length at any time point.
The study therefore concluded that daily vitamin D3 supplementation over 4 years may reduce the rate of telomere shortening in older adults. This suggests that by preserving telomere length, vitamin D3 can potentially delay cellular aging or senescence though further research is needed to better understand its long-term effects and underlying mechanisms N-3 fatty acids showed no effect on telomere length in the study, implying that nutritional supplements vary in their impact on biological aging.
Reference
1. Haidong Zhu, et al. Vitamin D3 and marine ω-3 fatty acids supplementation and leukocyte telomere length: 4-year findings from the VITamin D and OmegA-3 TriaL (VITAL) randomized controlled trial. Am J Clin Nutr. 2025 May 21:S0002-9165(25)00255-2. doi: 10.1016/j.ajcnut.2025.05.003.
emedinexus.com