Table 3.

Associations of CKD status with change in vitamin D metabolic ratios

Covariate AdjustmentsDifference in Change in the 24,25(OH)2D3-to-25(OH)D3 Ratio, pg/ngDifference in Change in the 1,25(OH)2D3-to-25(OH)D3 Ratio, pg/ng
Difference (95% Confidence Interval)P ValueDifference (95% Confidence Interval)P Value
None (unadjusted)−41.29 (−64.09 to −18.39)<0.0010.59 (0.01 to 1.18)0.05
Age/sex/race, site, BMI−30.40 (−53.9 to −6.88)0.010.7 (−0.10 to 1.30)0.02
Age/sex/race, site, BMI + FGF-23 + PTH−22.40 (−49.0 to 4.30)0.100.8 (0.13 to 1.47)0.02
  • Cell contents represent the difference in change in vitamin D metabolic ratios comparing participants with CKD with those in non-CKD group [(change in vitamin D metabolic ratio from baseline to post-treatment in CKD group) − (change in vitamin D metabolic ratio from baseline to post-treatment in the non-CKD group)], with 95% confidence intervals and P values. Model 1: age, sex, race, site of enrollment, and BMI were assessed as potential confounding factors in the differences in change noted in the vitamin D metabolic ratios between the participants with CKD and the participants without CKD. Model 2 was adjusted for all covariates in model 1 in addition to baseline PTH and FGF-23 to assess if PTH and/or FGF-23 were potential mediators in the differences observed in the vitamin D metabolic ratios by CKD status. 24,25(OH)2D3-to-25(OH)D3 ratio, the ratio of 24,25-dihydroxyvitamin D3 to 25-hydroxyvitamin D3; 1,25(OH)2D3-to-25(OH)D3 ratio, the ratio of 1,25-dihydroxyvitamin D3 to 25-hydroxyvitamin D3; BMI, body mass index; FGF-23, fibroblast growth factor-23; PTH, parathyroid hormone.