Epigenetic Clock and Leukocyte Telomere Length Are Associated with Vitamin D Status but not with Functional Assessments and Frailty in the Berlin Aging Study II.
Level 4 - case-series / case-control
Cross-sectional observational study
PubMed 32324874 · doi:10.1093/gerona/glaa101
What was done
Researchers analyzed cross-sectional data from 1,649 participants (~50% female, aged 22–37 and 60–84 years) in the Berlin Aging Study II. They measured biological aging using a 7-CpG epigenetic clock (DNA methylation age acceleration) and relative leukocyte telomere length (rLTL) via quantitative real-time PCR. Serum 25-hydroxyvitamin D [25(OH)D] was categorized as deficient (<25 nmol/L) or insufficient (<50 nmol/L). Associations between these biological aging markers, vitamin D status, functional capacity tests, and the Fried frailty score were evaluated with ANOVA and covariate-adjusted models.
What was found
Vitamin D-sufficient individuals had 1.4 years lower mean DNAm age acceleration (p < .05) and 0.11 longer rLTL (p < .001) compared to deficient participants. In covariate-adjusted analyses, vitamin D sufficiency remained associated with lower DNAm age acceleration (β = 1.060, p = .001) and longer rLTL (β = -0.070, p < .001) compared to nonsufficient subjects. Neither DNAm age acceleration nor rLTL showed significant associations with the Fried frailty score or general functional assessments, with the sole exception of the clock drawing test associating with DNAm age acceleration in a subgroup of older men (β = 1.898, p = .002).
Why it matters
This study links adequate vitamin D levels to molecular markers of slower biological aging (epigenetic clock and telomere length), while showing these cellular biomarkers do not neatly map onto clinical frailty or physical functional capacity in cross-sectional data.
Limits
The study is cross-sectional, precluding causal inference or determination of whether vitamin D deficiency accelerates biological aging. The cohort is split into two discrete age brackets (younger and older adults) rather than a continuous lifespan distribution. Functional and frailty outcomes were largely null, and longitudinal data were not evaluated to assess predictive capacity over time.
Cited by
- supports Vitamin D deficiency is associated with accelerated epigenetic aging.