Table 1.
Baseline characteristics of participants aged 60+ years in the VITAL cognitive substudy by vitamin D supplement assignment for VITAL-Cog (n = 3424) and CTSC-Cog (n = 794).
| VITAL-Cog (n = 3424) | CTSC-Cog (n = 794) | |||
|---|---|---|---|---|
| Vitamin D Group (n = 1710) | Placebo Group (n = 1714) | Vitamin D3 Group (n = 396) | Placebo Group (n = 398) | |
| Mean (SD) | ||||
| Age at 1st interview, yearsa (n = 2984 in VITAL-Cog; n = 776 in CTSC-Cog) |
71.9 (5.4) (n = 1480) |
71.8 (5.4) (n = 1504) |
66.9 ± 5.2 (n = 385) |
67.3 ± 5.4 (n = 391) |
| Age at 2nd interview, yearsa (n = 2923 in VITAL-Cog; n = 515 in CTSC-Cog) |
73.3 (5.7) (n = 1466) |
73.4 (5.7) (n = 1457) |
69.2 ± 5.1 (n = 254) |
69.8 ± 5.6 (n = 261) |
| Cognitive test scores at 1st interview | ||||
| VITAL-Cog only tests | ||||
| TICS | 33.9 (2.8) | 34.0 (2.8) | – | – |
| OTMT-Part A (s) | 10.7 (3.9) | 10.3 (3.3) | – | – |
| OTMT-Part B (s) | 38.0 (24.2) | 37.9 (24.1) | – | – |
| Digit span backwards | 6.7 (2.3) | 6.8 (2.4) | – | – |
| CTSC-Cog only tests | ||||
| 3MS | – | – | 94.8 ± 4.9 | 94.9 ± 4.4 |
| TMT-Part A (s) | – | – | 29.2 ± 11.5 | 29.8 ± 9.4 |
| TMT-Part B (s) | – | – | 80.0 ± 42.9 | 82.5 ± 44.2 |
| Vegetable naming test | – | – | 15.6 ± 4.6 | 15.4 ± 4.5 |
| Common tests across VITAL-Cog and CTSC-Cog | ||||
| TICS 10-word list recall-immediate | 4.6 (1.7) | 4.7 (1.7) | 4.7 ± 1.3 | 4.7 ± 1.3 |
| TICS 10-word list recall-delayed | 2.7 (1.9) | 2.7 (1.9) | 2.0 ± 1.8 | 1.9 ± 1.7 |
| EBMT-immediate | 9.6 (1.7) | 9.6 (1.8) | 9.7 ± 1.7 | 9.7 ± 1.6 |
| EBMT-delayed | 9.3 (1.8) | 9.3 (1.9) | 9.3 ± 1.7 | 9.3 ± 1.7 |
| Animal naming test | 19.4 (5.5) | 19.7 (5.6) | 21.1 ± 5.9 | 20.3 ± 6.1 |
| Global composite score | − 0.02 (0.57) | 0.02 (0.57) | 0.02 (0.63) | − 0.02 (0.56) |
| Baseline serum 25(OH)D (ng/mL) | 32.2 (9.8) | 32.5 (9.6) | 28.0 (8.3) | 29.1 (9.1) |
| n (%) | ||||
| Omega-3 assignment | ||||
| Active group | 844 (49.4%) | 855 (49.9%) | 198 (50.0%) | 198 (49.8%) |
| Placebo group | 866 (50.6%) | 859 (50.1%) | 198 (50.0%) | 200 (50.3%) |
| Sex | ||||
| Female | 1011 (59.1%) | 1005 (58.6%) | 205 (51.8%) | 195 (49.0%) |
| Male | 699 (40.9%) | 709 (41.4%) | 191 (48.2%) | 203 (51.0%) |
| Self-reported race/ethnicity | ||||
| Non-Hispanic White | 1184 (71.3%) | 1245 (73.8%) | 341 (88.1%) | 345 (89.2%) |
| Black | 387 (23.3%) | 356 (21.1%) | 18 (4.7%) | 26 (6.7%) |
| Other race/ethnicityb | 90 (5.4%) | 85 (5.0%) | 28 (7.2%) | 16 (4.1%) |
| Highest attained education | ||||
| High school or under | 189 (11.1%) | 183 (10.7%) | 29 (7.3%) | 34 (8.5%) |
| College | 678 (39.7%) | 664 (38.9%) | 138 (34.9%) | 152 (38.2%) |
| Post-graduate studies | 842 (49.3%) | 861 (50.4%) | 228 (57.7%) | 212 (53.3%) |
| Depressionc | ||||
| No | 1363 (82.7%) | 1383 (82.9%) | 324 (83.7%) | 309 (79.8%) |
| Yes | 285 (17.3%) | 285 (17.1%) | 63 (16.3%) | 78 (20.2%) |
3MS Modified Mini-Mental Status exam (range = 0–100)33; CTSC Clinical and Translational Science Collaborative Center for VITAL in Boston, MA; EBMT East Boston Memory Test (range = 0–12)34; OTMT Oral Trail Making Test (range = 0–120 s)35,36; SD standard deviation; TICS Telephone Interview for Cognitive Status (range = 0–41)37; TMT Trail Making Test (range = 0–150 s for part A and range = 0–300 s for part B)38,39.
aCharacteristics as of randomization unless noted otherwise; for categorical variables, the percentages do not add to 100% due to rounding errors and numbers do not add to the total due to missing values, which were taken out of descriptive statistical analyses. In the VITAL-Cog, 501 completed only the baseline, 440 completed only the 2nd assessment and 2483 completed both assessments. In the CTSC-Cog, 497 completed both assessments, 279 completed only the baseline and 18 completed only the 2nd assessment.
b“Other race/ethnicity” includes “Non-Black/African-American Hispanic”, “Asian”, “Native Hawaiian or other Pacific Islander” or “American Indian/Alaska Native”.
cDepression is defined as a lifetime history of a depression diagnosis or of treatment for depression; current use of antidepressants; experiencing two or more weeks of depression in the past 2 years or scoring 10 points or higher on the Patient Health Questionnaire-8.