The more vitamin D in your body, the younger your DNA is, researchers at the London School of Medicine suggest in the American Journal of Clinical Nutrition. Higher levels of the vitamin D metabolite 25-hydroxyvitamin D may be correlated with longer telomeres in the genome.
Telomeres are like the little plastic cover at the end of a shoelace. If that cover isn’t there, the shoelace starts to fray. The telomeres form a cover to protect the repetitive DNA ends of the chromosomes.
Each time cells divide the cover gets smaller. If it disappears, the genetic material starts to fray and is destroyed. The length of the telomeres is therefore an indicator of how worn out the genetic material is. The longer the telomere, the longer you still have to live. At least, according to a popular theory.
The Brits measured the length of the telomeres in the white blood cells of over two thousand women. They also measured the concentration of 25-hydroxyvitamin D in the women’s blood. This is the active vitamin D metabolite that is made when the skin is exposed to sunlight.
The researchers also measured the concentration of C-reactive protein (CRP) in the women’s blood. CRP is an inflammatory protein that helps get rid of undesirable intruders, but it is also a marker of processes in which the body’s immune system turns against its own cells.
Thomas von Zglinicki of the University of Newcastle told the BBC that he is not sure whether vitamin D actually slows down the aging process. At the individual level, the length of telomeres is not a very reliable predictor of aging, he says. “Other studies have found that people who die at the same age can have significant differences in their telomere length – up to 30 times the differences described in this study.”
Higher serum vitamin D concentrations are associated with longer leukocyte telomere length in women.
Vitamin D is a potent inhibitor of the proinflammatory response and thereby diminishes turnover of leukocytes. Leukocyte telomere length (LTL) is a predictor of aging-related disease and decreases with each cell cycle and increased inflammation.
The objective of the study was to examine whether vitamin D concentrations would attenuate the rate of telomere attrition in leukocytes, such that higher vitamin D concentrations would be associated with longer LTL.
Serum vitamin D concentrations were measured in 2160 women aged 18-79 y (mean age: 49.4) from a large population-based cohort of twins. LTL was measured by using the Southern blot method.
Age was negatively correlated with LTL (r = -0.40, P < 0.0001). Serum vitamin D concentrations were positively associated with LTL (r = 0.07, P = 0.0010), and this relation persisted after adjustment for age (r = 0.09, P < 0.0001) and other covariates (age, season of vitamin D measurement, menopausal status, use of hormone replacement therapy, and physical activity; P for trend across tertiles = 0.003). The difference in LTL between the highest and lowest tertiles of vitamin D was 107 base pairs (P = 0.0009), which is equivalent to 5.0 y of telomeric aging. This difference was further accentuated by increased concentrations of C-reactive protein, which is a measure of systemic inflammation.
Our findings suggest that higher vitamin D concentrations, which are easily modifiable through nutritional supplementation, are associated with longer LTL, which underscores the potentially beneficial effects of this hormone on aging and age-related diseases.
PMID: 17991655 [PubMed - indexed for MEDLINE] PMCID: PMC2196219