Table 3.

The primary and secondary outcomes (6-month changes) by treatment type

VariablePlaceboVitamin D TreatmentTreatment versus Placeboa,bTreatment versus Placeboc
Pulse wave velocity, m/sn=30n=57
 Unadjusted baseline, mean (SD)10.6 (3.6)12.3 (4.0)
 Unadjusted 6 mo, mean (SD)11.7 (3.5)11.8 (3.7)
 Unadjusted change (95% CI) at 6 mo1.1 (−0.1 to 2.2)−0.4 (−1.2 to 0.4)−1.5 (−2.9 to −0.1)
P valuea0.04
 Adjusted change (95% CI) at 6 mob0.7 (−0.3 to 1.7)−0.2 (−0.9 to 0.5)−0.9 (−2.1 to 0.4)−0.9 (−1.9 to 0.2)
P valueb0.170.10
Systolic BP, mmHgn=35n=67
 Unadjusted baseline, mean (SD)138.8 (16.6)137.7 (17.6)
 Unadjusted 6 mo, mean (SD)139.3 (10.8)139.8 (19.3)
 Unadjusted change (95% CI) at 6 mo0.5 (−5.0 to 6.0)2.2 (−1.8 to 6.1)1.7 (−5.1 to 8.4)
P valuea0.63
 Adjusted change (95% CI) at 6 mob0.9 (−3.9 to 5.6)2.0 (−1.5 to 5.4)1.1 (−4.8 to 7.0)N/A
P valueb0.70
Diastolic BP, mmHgn=35n=67
 Unadjusted baseline, mean (SD)73.7 (11.8)71.4 (11.6)
 Unadjusted 6 mo, mean (SD)75.1 (10.1)72.8 (11.8)
 Unadjusted change (95% CI) at 6 mo1.4 (−1.6 to 4.4)1.4 (−0.8 to 3.6)−0.0 (−3.8 to 3.7)
P valuea0.99
 Adjusted change (95% CI) at 6 mob1.9 (−0.8 to 4.6)1.1 (−0.9 to 3.1)−0.8 (−4.2 to 2.6)−0.8 (−4.2 to 2.6)
P valueb0.650.65
Urine ACR, ln(mg/g)n=35n=63
 Unadjusted baseline, mean (SD)5.3 (2.1)5.2 (1.8)
 Unadjusted 6 mo, mean (SD)5.4 (2.1)5.1 (2.0)
 Unadjusted change (95% CI) at 6 mo0.1 (−0.1 to 0.3)−0.0 (−0.2 to 0.1)−0.1 (−0.4 to 0.1)
P valuea0.35
 Adjusted change (95% CI) at 6 mob0.1 (−0.1 to 0.3)−0.0 (−0.2 to 0.1)−0.1 (−0.4 to 0.1)−0.1 (−0.4 to 0.1)
P valueb0.350.35
Calcium, mg/dln=35n=67
 Unadjusted baseline, mean (SD)9.3 (0.4)9.3 (0.5)
 Unadjusted 6 mo, mean (SD)9.0 (1.2)9.4 (0.5)
 Unadjusted change (95% CI) at 6 mo−0.3 (−0.5 to −0.0)0.1 (−0.1 to 0.3)0.4 (−0.1 to 0.7)
P valuea0.02
 Adjusted change (95% CI) at 6 mob−0.3 (−0.5 to −0.0)0.1 (−0.1 to 0.3)0.4 (−0.1 to 0.7)0.4 (−0.1 to 0.7)
P valueb0.020.02
Phosphate, mg/dln=35n=67
 Unadjusted baseline, mean (SD)3.5 (0.7)3.5 (0.7)
 Unadjusted 6 mo, mean (SD)3.6 (0.8)3.6 (0.8)
 Unadjusted change (95% CI) at 6 mo0.2 (−0.0 to 0.4)0.2 (0.0 to 0.3)−0.0 (−0.2 to 0.2)
P valuea0.99
 Adjusted change (95% CI) at 6 mob0.2 (−0.0 to 0.4)0.2 (0.0 to 0.3)−0.0 (−0.2 to 0.2)0.0 (−0.2 to 0.2)
P valueb0.980.96
PTH, ln(pg/ml)n=35n=66
 Unadjusted baseline, mean (SD)4.9 (0.7)4.6 (0.7)
 Unadjusted 6 mo, mean (SD)5.0 (0.8)4.3 (0.8)
 Unadjusted change (95% CI) at 6 mo0.1 (−0.0 to 0.3)−0.3 (−0.5 to −0.2)−0.5 (−0.7 to −0.3)
P valuea<0.001
 Adjusted change (95% CI) at 6 mob0.2 (−0.0 to 0.3)−0.4 (−0.5 to −0.2)−0.5 (−0.7 to −0.3)−0.5 (−0.7 to −0.4)
P valueb<0.001<0.001
FGF-23, ln(pg/ml)n=33n=65
 Unadjusted baseline, mean (SD)5.0 (0.7)4.7 (0.9)
 Unadjusted 6 mo, mean (SD)5.0 (0.9)4.9 (1.0)
 Unadjusted change (95% CI) at 6 mo0.1 (−0.1 to 0.3)0.2 (0.1 to 0.3)0.1 (−0.1 to 0.3)
P valuea0.23
 Adjusted change (95% CI) at 6 mob0.1 (−0.1 to 0.3)0.2 (0.1 to 0.3)0.1 (−0.1 to 0.3)0.1 (−0.1 to 0.3)
P valueb0.240.26
CRP, ln(mg/L)n=34n=65
 Unadjusted baseline, mean (SD)0.3 (1.0)0.5 (1.2)
 Unadjusted 6 mo, mean (SD)0.2 (1.0)0.5 (1.1)
 Unadjusted change (95% CI) at 6 mo−0.1 (−0.4 to 0.2)0.0 (−0.2 to 0.2)0.1 (−0.2 to 0.5)
P valuea0.45
 Adjusted change (95% CI) at 6 mob−0.1 (−0.4 to 0.1)0.1 (−0.1 to 0.2)0.2 (−0.1 to 0.5)0.2 (−0.1 to 0.5)
P valueb0.210.23
25(OH)D, ng/mln=33n=64
 Unadjusted baseline, mean (SD)29.1 (11.4)26.3 (10.1)
 Unadjusted 6 mo, mean (SD)26.2 (11.6)59.0 (51.2)
 Unadjusted change (95% CI) at 6 mo−2.9 (−17.1 to 11.4)32.7 (22.5 to 42.9)35.6 (18.1 to 53.1)
P valuea<0.001
 Adjusted change (95% CI) at 6 mob−2.6 (−17.0 to 11.7)32.6 (22.3 to 42.9)35.2 (17.5 to 53.0)35.2 (17.5 to 53.0)
P valueb<0.001<0.001
1,25(OH)2D, pg/mln=33n=63
 Unadjusted baseline, mean (SD)20.3 (7.4)22.8 (10.6)
 Unadjusted 6 mo, mean (SD)21.7 (7.6)27.3 (12.6)
 Unadjusted change (95% CI) at 6 mo1.4 (−2.6 to 5.4)4.5 (1.6 to 7.4)3.1 (−1.8 to 8.1)
P valuea0.21
 Adjusted change (95% CI) at 6 mob,c0.5 (−3.1 to 4.1)5.0 (2.4 to 7.6)4.5 (0.1 to 9.0)4.9 (0.9 to 8.8)
P valueb,c0.050.02
  • SI conversion factors: to convert urine ACR to mg/mmol, multiply by 0.113; to convert calcium to mmol/L, multiply by 0.25; to convert phosphate to mmol/L, multiply by 0.323; to convert PTH to pmol/L, multiply by 0.106; to convert 25(OH)D to nmol/L, multiply by 2.496; to convert 1,25(OH)2D to pmol/L, multiply by 2.6. 95% CI, 95% confidence interval; ACR, albumin-to-creatinine ratio; ln, natural logarithm; PTH, parathyroid hormone; FGF-23, fibroblast growth factor 23; CRP, C-reactive protein; 25(OH)D, 25-hydroxyvitamin D; 1,25(OH)2D, 1,25-dihydroxyvitamin D.

  • a Unadjusted mean change, 95% CI, and P value for treatment effects compared using the t test.

  • b Adjusted mean change, 95% CI, and P value for treatment effects, with the respective baseline value as covariate, compared using analysis of covariance.

  • c Mixed model results: estimates, 95% CI, and P value for treatment effects reported. All models include the treatment effect and respective baseline variable. The participants and treatment were modeled as random effects.