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 populationbased cohort of twins. LTL was measured by using the Southern blot method. Results: Age was negatively correlated with LTL (r ҃ Ҁ0.40, 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.

Recent studies of inherited disorders of phosphate metabolism have shed new light on the understanding of phosphate metabolism. Phosphate has important functions in the body and several mechanisms have evolved to regulate phosphate balance including vitamin D, parathyroid hormone and phosphatonins such as fibroblast growth factor-23 (FGF23). Disorders of phosphate homeostasis leading to hypo-and hyperphosphataemia are common and have clinical and biochemical consequences. Notably, recent studies have linked hyperphosphataemia with an increased risk of cardiovascular disease. This review outlines the recent advances in the understanding of phosphate homeostasis and describes the causes, investigation and management of hypo-and hyperphosphataemia.

Menopausal status impacts leukocyte telomere length and its relation with insulin resistance and inflammation in women.

Shortened leukocyte telomere length is independently associated with a decrease in BMD and the presence of osteoporosis in women. Our data provide evidence that leukocyte telomere length could be a marker of biological aging of bone.