Associations of 25 Hydroxyvitamin D and High Sensitivity C-reactive Protein Levels in Early Life.

Vitamin D deficiency and elevated high sensitivity C-reactive protein (hs-CRP) have been associated with several health outcomes, but knowledge on early life trajectories and association between 25 hydroxyvitamin D (25(OH)D) and hs-CRP is lacking. We investigated the association between longitudinal measurements of 25(OH)D and hs-CRP, respectively, from pregnancy to childhood and throughout childhood in two Danish mother-child cohorts-the COPSAC and COPSAC. In COPSAC, there was an association between 25(OH)D concentrations at week 24 in pregnancy and at age 6 months in childhood ( 633): estimate (95% CI); 0.114 (0.041;0.187), 0.002, and between 25(OH)D at age 6 months and 6 years ( 475): 0.155 (0.083;0.228), 0.001. This was also demonstrated in the COPSAC cohort between 25(OH)D concentrations in cord blood and at age 4 years ( 188): 0.294 (0.127;0.461), 0.001 and at age 6 months and 4 years ( 264): 0.260 (0.133;0.388), 0.001. In COPSAC, we also found an association between hs-CRP at age 6 months and 12 years in childhood ( 232): 0.183 (0.076;0.289), 0.001. Finally, we found a negative association between the cross-sectional measurements of 25(OH)D and hs-CRP at age 6 months ( 613) in COPSAC: -0.004 (-0.008;-0.0004), 0.030, but this was not replicated in COPSAC. In this study, we found evidence of associations across timepoints of 25(OH)D concentrations from mid-pregnancy to infancy and through childhood and associations between hs-CRP levels during childhood, although with weak correlations. We also found a negative cross-sectional association between 25(OH)D and hs-CRP concentrations in COPSAC proposing a role of vitamin D in systemic low-grade inflammation, though this association was not present in COPSAC.