TABLE 1.
Baseline characteristics by treatment group1
| Variables | Vitamin D (n = 22) | Placebo (n = 24) | P |
| Age (y) | 62.3 ± 10.52 | 62.6 ± 8.9 | 0.90 |
| BMI (kg/m2) | 32.8 ± 5.1 | 31.5 ± 7.5 | 0.49 |
| Men [n (%)] | 20 (90.9) | 22 (91.7) | 0.93 |
| African American [n (%)] | 11 (50.0) | 11 (45.8) | 0.77 |
| eGFR (mL · min−1 · 1.73 m−2) | 62.5 ± 15.6 | 61.2 ± 15.7 | 0.78 |
| CKD stage 2/3 (n)3 | 11/11 | 10/14 | 0.47 |
| Hypertension [n (%)] | 20 (90.9) | 21 (87.5) | 0.71 |
| Total diabetes [n (%)]4 | 18 (81.8) | 17 (70.8) | 0.38 |
| Type 2 diabetes [n (%)] | 19 (86.4) | 13 (54.2) | 0.02 |
| Serum phosphorus (mg/dL) | 3.8 ± 0.6 | 3.7 ± 0.7 | 0.49 |
| Serum calcium (mg/dL) | 9.4 ± 0.4 | 9.5 ± 0.3 | 0.15 |
| Serum 25(OH)D (ng/mL) | 26.7 ± 6.8 | 32.1 ± 8.7 | 0.03 |
| Vitamin D insufficient [25(OH)D <30 ng/mL] [n (%)] | 15 (68.2) | 11 (45.8) | 0.13 |
| Serum PTH (pg/mL) | 89.1 ± 49.2 | 78.21 ± 22.8 | 0.61 |
| PTH >70 pg/mL [n (%)] | 11 (50) | 14 (58.3) | 0.57 |
| FGF23 (RU/mL) | 55.5 ± 34.8 | 42.5 ± 26.7 | 0.16 |
| SBP (mm Hg) | 127 ± 15 | 131 ± 17 | 0.44 |
| DBP (mm Hg) | 71 ± 10 | 73 ± 10 | 0.45 |
| Summer and autumn enrollment [n (%)] | 15 (68.2) | 22 (91.7) | 0.04 |
| Vitamin D supplement use [n (%)] | 3 (13.6) | 11 (45.8) | 0.02 |
| Dietary vitamin D (IU/d)5 | 108 ± 74 [11] | 180 ± 129 [11] | 0.12 |
1
P values were determined by using a 2-sample t or chi-square test. CKD, chronic kidney disease; DBP, diastolic blood pressure; eGFR, estimated glomerular filtration rate; FGF23, fibroblast growth factor-23; PTH, parathyroid hormone; RU, relative units; SBP, systolic blood pressure; 25(OH)D, 25-hydroxyvitamin D.
2
Mean ± SD (all such values).
3
One subject with stage 1 CKD was grouped with stage 2 subjects, and one subject with stage 4 CKD was grouped with stage 3 subjects.
4
Includes type 1 and 2 diabetes.
5
n in brackets.