Longer Telomeres Associated with Higher Vitamin D Levels

Researchers in London report that higher vitamin D blood levels in women are associated with longer leukocyte (a type of white blood cell) telomere length.

The study reports that shorter leukocyte telomeres are found in individuals with chronic inflammation, because the inflammatory response results in an increased turnover (replication) of leukocytes. Vascular diseases and autoimmune diseases, as well as cigarette smoking and obesity, have also been associated with shorter leukocyte telomeres. They report that a recent randomized case-control analysis revealed that shortened leukocyte telomeres were an independent risk factor for coronary heart disease (CHD), not surprisingly, as inflammation is a risk factor for CHD and could also be the cause of the shorter telomeres.

In this study, the LTL (leukocyte telomere length) in the lowest tertile (third) of 25-hydroxyvitamin D was 6.97; in the middle tertile, LTL was 7.02; and in the highest tertile of 25-hydroxyvitamin D, LTL was 7.08. The researchers also report, “Vitamin D supplement information was available on a subset of the study population (n = 700). Vitamin D supplement users had longer LTLs, despite adjustment for age, season of vitamin D measurement, menopausal status, use of hormone replacement therapy, and physical activity, than did nonusers. Mean adjusted LTL in subjects who did not use vitamin D supplements was 6.95 kb, whereas that of current users of vitamin D supplements was 7.06 kb; however, this difference was not statistically significant . . .” at <0.06. (<0.05 would be significant, so this result just barely fails to reach 95% significance.)

It is also useful to consider that most vitamin D users received their vitamin D as part of a one-per-day-type multivitamin supplement, where the typical dose would be 400 IU of vitamin D2. Based on emerging research, this is way too low. However blood tests are now easily available to help manage plasma vitamin D levels.

This study was performed by researchers at the Twin Research and Genetic Epidemiology, St Thomas' Hospital, King's College, London School of Medicine, London, United Kingdom, and published in the American Journal of clinical Nutrition.

Abstract

BACKGROUND: 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. OBJECTIVE: 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. DESIGN: 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. RESULTS: 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. CONCLUSION: 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.

Source

Richards JB, Valdes AM, Gardner JP, Paximadas D, Kimura M, Nessa A, Lu X, Surdulescu GL, Swaminathan R, Spector TD, Aviv A. Higher serum vitamin D concentrations are associated with longer leukocyte telomere length in women. Am J Clin Nutr. 2007 Nov;86(5):1420-5. PMID: 17991655 [PubMed - indexed for MEDLINE]

Key concepts: telomere length, Vitamin D