Vitamin D levels during pregnancy are associated with offspring telomere length : a longitudinal mother-child study

Context: Leukocyte telomere length (LTL) is a biomarker of biological aging and is associated with metabolic diseases such as type 2 diabetes. Insufficient maternal vitamin D was associated with increased risk for many diseases and adverse later life outcomes. Objective: This study investigates the relationship between vitamin D levels and offspring LTL at early life. Methods: This observational, longitudinal, hospital-based cohort study included eligible mother-child pairs from the HAPO Hong Kong Field Centre, with 853 offspring at age 6.96±0.44 (mean±SD) years. LTL was measured using real-time polymerase chain reaction while serum vitamin D metabolites 25(OH)D2, 25(OH)D3, and 3-epi-25(OH)D3 were measured in maternal blood (at gestation 24-32 weeks) and cord blood by liquid chromatography-mass spectrometry. Results: LTL at follow-up was significantly shorter in boys compared with girls (P<0.001) at age 7. Childhood LTL was negatively associated with childhood BMI (β±SE=-0.016±0.007)(P=0.02) and HOMA-IR (β±SE=-0.065±0.021)(P=0.002). Multiple linear regression was used to evaluate the relationship between 25(OH)D and LTL, with covariate adjustments. Childhood LTL was positively correlated with total maternal 25(OH)D (0.048±0.017) (P=0.004) and maternal 3-epi-25(OH)D3 (0.05±0.017) (P=0.003), even after adjustment for covariates. A similar association was also noted for cord 3-epi-25(OH)D3 (0.037±0.018) (P=0.035) after adjustment for offspring sex and age. Conclusion: Our findings suggest 25(OH)D3 and 3-epi-25(OH)D3 in utero may impact on childhood LTLs, highlighting a potential link between maternal vitamin D and biological aging.