Table 1.

Baseline characteristics of the randomized participants by study arm

VariableAll ParticipantsPlaceboVitamin D Treatment
CalcitriolCalcifediolTotal Vitamin D Treatment
N11940394079
Age, mean (SD), yr65.8 (13.1)64.5 (12.2)66.9 (11.7)65.9 (15.3)66.4 (13.5)
Men, n (%) 81 (71)29 (73)28 (72)28 (70)56 (71)
Race, n (%)
 White77 (65)27 (68)23 (59)27 (68)50 (63)
 Asian22 (18)10 (25)6 (15)6 (15)12 (15)
 South Asian10 (8)3 (8)4 (10)3 (8)7 (9)
 Other10 (8)6 (15)4 (10)10 (13)
Diabetes, n (%)48 (40)15 (38)18 (46)15 (38)33 (42)
Cardiovascular  disease, n (%)41 (34)30 (38)14 (36)16 (40)11 (28)
Peripheral vascular  disease, n (%)8 (7)3 (8)3 (8)2 (5)5 (6)
Cerebral vascular  disease, n (%)10 (8)4 (10)2 (5)4 (10)6 (8)
Primary kidney disease, n (%)
 Diabetic nephropathy27 (23)8 (20)11 (29)8 (22)19 (25)
 Hypertensive nephropathy31 (27)12 (30)9 (24)10 (27)19 (25)
 GN28 (24)12 (30)7 (18)9 (24)16 (21)
 Polycystic6 (5)1 (3)4 (11)1 (3)5 (7)
 Tubulo-interstitial disease2 (2)1 (3)1 (3)2 (3)
 Other15 (13)4 (10)5 (13)6 (16)11 (15)
 Unknown6 (5)3 (8)1 (3)2 (5)3 (4)
Medications, n (%)
 Phosphate binder (calcium-based)37 (31)12 (30)13 (33)12 (30)25 (32)
 Statin92 (77)32 (80)32 (82)28 (70)60 (76)
 Bisphosphonate3 (3)2 (5)1 (3)1 (1)
 Warfarin9 (8)3 (8)4 (10)2 (5)6 (8)
BMI, mean (SD), kg/m228.7 (6.6)28.8 (5.3)29.7 (5.9)29.0 (5.0)28.6 (7.2)
Systolic BP, mean  (SD), mmHg138.5 (17.1)140.5 (17.2)134.9 (12.5)140.0 (20.3)137.5 (17.1)
Diastolic BP, mean  (SD), mmHg72.3 (11.6)74.2 (12.3)70.4 (9.7)72.1 (12.5)71.3 (11.2)
Heart rate, mean  (SD), bpm66.7 (11.2)66.9 (12.9)67.9 (11)65.5 (9.9)66.6 (10.3)
Radial artery pulse pressure, mean (SD), mmHg15.0 (9.1)15.5 (10.6)14.6 (8.3)14.8 (8.3)14.7 (8.3)
Augmentation index, mean (SD), %24.4 (10.5)24.0 (11.0)25.4 (8.8)23.7 (11.6)24.6 (10.3)
Pulse wave velocity, mean (SD), m/s11.5 (3.9)10.7 (3.7)11.6 (3.8)12.1 (4.2)11.9 (4.0)
eGFR-MDRD, mean (SD), ml/min per 1.73 m228.9 (8.9)26.4 (7.4)29.1 (9.0)31.1 (9.7)30.1 (9.4)
Urine ACR, median [IQR], mg/g151.8 [36.3–1161.1]303.6 [27.4–1465.5]101.8 [32.8–841.2]168.2 [49.6–802.2]137.6 [36.8–841.1]
Calcium, mean (SD), mg/dl9.3 (0.5)9.3 (0.4)9.3 (0.6)9.2 (0.5)9.3 (0.5)
Phosphate, mean (SD), mg/dl3.5 (0.6)3.5 (0.7)3.5 (0.6)3.5 (0.7)3.45 (0.6)
PTH, median [IQR], pg/ml102.8 [60.4–188.1]150.0 [75.4–232.0]84.0 [58.5–153.7]90.1 [57.1–150.9]87.3 [57.5–152.8]
FGF-23, median [IQR], pg/ml103.0 [69.4–236]142.3 [87–292.2]89.2 [59.7–136.8]101.6 [66.5–160.4]93.9 [66.4–222.9]
CRP, median [IQR], mg/L1.5 [0.7–4.2]1.4 [0.6–3.6]1.1 [0.6–3.0]2.9 [0.9–5.3]1.5 [0.7–4.8]
25(OH)D, mean (SD), ng/ml27.0 (11.0)29.4 (12.7)26.6 (10.7)25.2 (9.3)25.9 (10.0)
1,25(OH)2D, mean (SD), pg/ml21.8 (9.2)20 (7.2)21.7 (9.5)23.7 (10.6)22.7 (10)
  • 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. —, null; BMI, body mass index; bpm, beats per minute; eGFR-MDRD, eGFR calculated using the Modification of Diet in Renal Disease Study equation; ACR, albumin-to-creatinine ratio; IQR, interquartile range; 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.