Table 1.
Baseline Characteristics of the Study Population
| Characteristic | Overall | Randomized Group | P Value | |
|---|---|---|---|---|
| Vitamin D3 | Placebo | |||
| No.a | 212 | 108 | 104 | |
| Enrolled in protocol version 1 | 101 | 51 | 50 | |
| Enrolled in protocol version 2 | 111 | 57 | 54 | |
| Age, yb | .58 | |||
| Median | 22.0 | 22.0 | 22.0 | |
| Q1, Q3 | 21.0, 23.0 | 20.5, 24.0 | 21.0, 23.0 | |
| Sex at birth, No. (%) | .71 | |||
| Male | 179 (84) | 90 (83) | 89 (86) | |
| Female | 33 (16) | 18 (17) | 15 (14) | |
| Sexual maturity rating (Tanner stage)c, No. (%) | 1.00 | |||
| 2 | 1 (<1) | 1 (1) | 0 (0) | |
| 3 | 2 (1) | 1 (1) | 1 (1) | |
| 4 | 5 (2) | 3 (3) | 2 (2) | |
| 5 | 204 (96) | 103 (95) | 101 (97) | |
| Race, No. (%) | .64 | |||
| Black/African American | 157 (74) | 78 (72) | 79 (76) | |
| Other race | 55 (26) | 30 (28) | 25 (24) | |
| Hispanic ethnicity, No. (%) | 45 (21) | 21 (19) | 24 (23) | .51 |
| BMI, kg/m2 | .024 | |||
| Median | 23.6 | 24.5 | 22.7 | |
| Q1, Q3 | 21.2, 28.8 | 22.1, 28.7 | 20.9, 28.9 | |
| BMI, No. (%) | .26 | |||
| Underweight (<18.5 kg/m2) | 8 (4) | 3 (3) | 5 (5) | |
| Normal (18.5–24.9 kg/m2) | 116 (55) | 54 (50) | 62 (60) | |
| Overweight (25–29.9 kg/m2) | 43 (20) | 27 (25) | 16 (15) | |
| Obese (≥30 kg/m2) | 45 (21) | 24 (22) | 21 (20) | |
| Lifestyle, No. (%) | ||||
| Exercise once weekly or more | 136 (64) | 70 (65) | 66 (63) | .89 |
| Trying to lose weight | 73 (34) | 38 (35) | 35 (34) | .89 |
| Smoke cigarettes | 52 (25) | 26 (24) | 26 (25) | 1.00 |
| Drink alcohol | 77 (38) | 48 (45) | 29 (29) | .021 |
| Uses multivitamin or mineral supplement, No. (%) | 53 (25) | 34 (32) | 19 (18) | .028 |
| Daily energy intake, kcal/kg/day | .79 | |||
| Median | 35.4 | 36.4 | 35.0 | |
| Q1, Q3 | 23.3, 54.8 | 22.9, 53.3 | 23.3, 58.7 | |
| Calcium intake, mg/day | ||||
| Dietary | .65 | |||
| Median | 1014 | 1024 | 988 | |
| Q1, Q3 | 573, 1545 | 609, 1560 | 534, 1494 | |
| Supplementald | .15 | |||
| Median | 200 | 200 | 123 | |
| Q1, Q3 | 45, 210 | 100, 257 | 40, 200 | |
| Total | .47 | |||
| Median | 1023 | 1045 | 988 | |
| Q1, Q3 | 581, 1545 | 636, 1560 | 534, 1494 | |
| Inadequate total daily calcium intake for age, No. (%)e | 104 (49) | 51 (47) | 53 (51) | .68 |
| Vitamin D intake, IU/day | ||||
| Dietary | .20 | |||
| Median | 138 | 150 | 116 | |
| Q1, Q3 | 77, 239 | 75, 278 | 78, 216 | |
| Supplementalf | .82 | |||
| Median | 600 | 600 | 600 | |
| Q1, Q3 | 400, 1000 | 400, 1000 | 400, 1500 | |
| Total vitamin D intake, IU/day | .051 | |||
| Median | 147 | 174 | 119 | |
| Q1, Q3 | 82, 320 | 82, 377 | 82, 245 | |
| Daily total vitamin D intake, No. (%) | .013 | |||
| <300 IU | 157 (74) | 72 (67) | 85 (82) | |
| 300–600 IU | 34 (16) | 25 (23) | 9 (9) | |
| >600 IU | 21 (10) | 11 (10) | 10 (10) | |
| Season enrolled, No. (%) | .91 | |||
| Winter | 83 (39) | 44 (41) | 39 (38) | |
| Spring | 85 (40) | 43 (40) | 42 (40) | |
| Summer | 33 (16) | 15 (14) | 18 (17) | |
| Fall | 11 (5) | 6 (6) | 5 (5) | |
| Geographic latitude (degrees north), No. (%) | .81 | |||
| ≤35 | 73 (34) | 36 (33) | 37 (36) | |
| >35 to 40 | 72 (34) | 39 (36) | 33 (32) | |
| >40 | 67 (32) | 33 (31) | 34 (33) | |
| Serum vitamin D concentration, ng/mL | .41 | |||
| Median | 16.4 | 15.7 | 16.8 | |
| Q1, Q3 | 11.4, 23.9 | 12.1, 24.9 | 10.2, 22.7 | |
| Serum vitamin D concentration category, No. (%)e | .57 | |||
| Deficient (25-OHD <12 ng/mL) | 57 (27) | 27 (25) | 30 (29) | |
| Inadequate (25-OHD 12 to <20 ng/mL) | 75 (35) | 37 (34) | 38 (37) | |
| Adequate (25-OHD ≥20 to 50 ng/mL) | 78 (37) | 42 (39) | 36 (35) | |
| Excess (25-OHD >50 ng/mL) | 2 (1) | 2 (2) | 0 (0) | |
| Time since HIV diagnosis, y | .61 | |||
| Median | 2.0 | 2.0 | 2.0 | |
| Q1, Q3 | 1.0, 3.0 | 1.0. 3.0 | 1.0, 3.0 | |
| CD4 cell count, cells/μL | .32 | |||
| Median | 651 | 636 | 663 | |
| Q1, Q3 | 491, 832 | 473, 826 | 507, 844 | |
| CD4 cells (cells/μL), No. (%) | ||||
| 0 to <200 | 1 (<1) | 0 (0) | 1 (1) | .56 |
| 200 to ≤350 | 19 (9) | 12 (11) | 7 (7) | |
| 351 to ≤500 | 35 (17) | 18 (17) | 17 (16) | |
| >500 | 157 (74) | 78 (72) | 79 (76) | |
| Duration of prior TDF treatment, mo | .37 | |||
| Median | 19.0 | 20.5 | 17.5 | |
| Q1, Q3 | 11.0, 33.0 | 11.0, 33.5 | 12.0, 31.5 | |
| Antiretrovirals, No. (%) | .87 | |||
| Protease inhibitor | 66 (31) | 33 (31) | 33 (32) | |
| NNRTI | 87 (41) | 47 (44) | 40 (38) | |
| PI + NNRTI | 22 (10) | 11 (10) | 11 (11) | |
| INSTI | 37 (17) | 17 (16) | 20 (19) | |
| Efavirenz in ART, No. (%)g | 78 (37) | 44 (41) | 34 (33) | .26 |
| Ritonavir in ART, No. (%)g | 88 (42) | 44 (41) | 44 (42) | .89 |
Abbreviations: 25-OHD, 25-hydroxy vitamin D; ART, antiretroviral therapy; BMI, body mass index; HIV, human immunodeficiency virus; INSTI, integrase strand transfer inhibitor, NNRTI, nonnucleoside reverse transcriptase inhibitor; PI, protease inhibitor; TDF, tenofovir disoproxil fumarate.
aA total of 214 participants were enrolled. Two inadvertent enrollees are excluded from this table.
bData are shown as median (Q1, Q3) unless otherwise specified. Q1 and Q3 represent the first and third quartiles of the distribution, respectively.
cSexual maturity rating (Tanner stage) was determined by physical examination or self-assessment.
dThe median supplemental calcium intake was calculated only for those who used supplements (n = 23): 17 vitamin D3; 6 placebo.
eInstitute of Medicine criteria [21].
fThe median supplemental vitamin D intake was calculated only for those who used supplements (n = 24): 16 vitamin D3; 8 placebo.
gEver used efavirenz or ritonavir.