Vitamin D3 Supplementation Reduces Telomere Attrition

MONDAY, June 2, 2025 (HealthDay News) — Supplementation with vitamin D₃ is associated with reduced telomere attrition in adults aged 50 years and older, according to a study published online May 21 in the American Journal of Clinical Nutrition.

Haidong Zhu, Ph.D., from the Medical College of Georgia at Augusta University, and colleagues conducted a randomized, double-blind, placebo-controlled trial of vitamin D₃ (2,000 IU/day) and marine omega 3 fatty acid (n-3 FAs; 1g/day) supplementation for five years in a representative sample of U.S. women aged 55 years and older and men aged 50 years and older. Leukocyte telomere length (LTL) was measured in 2,571 samples from 1,031 participants at baseline, year 2, and year 4.

The researchers found that vitamin D₃ supplementation significantly decreased LTL attrition by 0.14 kilo base pairs (kb) over four years compared with placebo. LTLs were about 0.035 kb higher per year of follow-up in the vitamin D₃ supplementation group compared with the placebo group in an overall trend analysis. No significant effect was seen on LTL at either year 2 or year 4 with marine n-3 FA supplementation.

“In the VITAL-Telomere study, vitamin D₃ supplementation reduced telomere attrition and preserved telomere length, supporting an anticellular aging effect of vitamin D,” the authors write. “Our findings underscore the potential benefits of vitamin D on biological aging and age-related diseases.”

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