Vitamin D as predictor of telomere length in the transition from child to adolescent

Introduction Telomere length is seen as marker for healthy ageing, as accelerated shortening is involved in the development of age-related diseases, including cardiovascular disease. Vitamin D might influence telomere length due to anti-inflammatory activities, because inflammation could decrease telomere length. Evidence supporting this theory is mainly from studies in adults, whether vitamin D in children is a predictor of telomere length is unknown. Therefore, this study investigated the role of vitamin D on telomere length in the transition from childhood to (early) adolescence. Methods Healthy Belgian children ( n  = 142) were followed-up between 2010–2015 (aged 4.7–10.7 years old at baseline, 50.4% boys). Serum vitamin D (25-hydroxy vitamin D) concentrations were measured at baseline and in 2015 using standardized protocols. Average relative telomere lengths were measured in blood samples using a quantitative real-time PCR method. Cross-sectional and longitudinal age and sex adjusted mixed linear regression models addressed the association between vitamin D and telomere length. Results Telomere length was shorter with increasing age ( P  = 0.01). Vitamin D was not associated with telomere length in cross-sectional analysis combining both sexes, but in boys higher vitamin D was related to longer telomeres. An interquartile increase in vitamin D (9.4 ng/mL) was associated with a 2.5% (95% confidence interval: 0.1 to 4.9%; P  = 0.04) increase in telomere length. Longitudinal analysis showed similar results for boys ( P  = 0.02). Conclusion This study over a 5-year period suggests that higher vitamin D concentrations are associated with longer telomere length in boys. These findings highlight the potential beneficial effects of vitamin D on ageing, especially since vitamin D concentrations might be easily adjustable through nutritional supplements.