Vitamin D3 and Marine Omega-3 Fatty Acids Supplementation and Leukocyte Telomere Length: 4-Year Findings from the VITAL Randomized Controlled Trial https://www.sciencedirect.com/science/article/abs/pii/S0002916525002552 4-years of supplementation with 2000 IU/day vitamin D3 reduced telomere attrition by 140 bp, suggesting that vitamin D3 daily supplementation with or without n-3 FAs might have a role in counteracting telomere erosion or cell senescence https://www.dailymail.co.uk/health/article-14736021/breakthrough-harvard-study-common-supplement-reverses-aging.html 2000 international units (IU) in pill form every day, the equivalent of one 3.5oz serving of salmon, reverses aging (Harvard study)