Associations of age, race, BMI, and month of blood sample with plasma vitamin D concentration: SELECT
| Unadjusted vitamin D concentrations | Adjusted vitamin D concentrationsa | |||||||
|---|---|---|---|---|---|---|---|---|
| Mean (SD) | Pb | <37.5 N (%)c | 37.5–<50 N (%)c | Mean (SD) | Pb | <37.5 N (%)c | 37.5–<50 N (%)c | |
| Total | 69.2 (29.7) | 635 (13.4) | 697 (14.7) | 69.2 (28.8) | 578 (12.2) | 697 (14.7) | ||
| Age, y | <0.001 | <0.001 | ||||||
| 50–54 | 46.6 (25.2) | 72 (43.6) | 36 (21.8) | 65.5 (24.6) | 10 (6.1) | 30 (18.2) | ||
| 55–59 | 66.1 (28.9) | 202 (15.9) | 210 (16.5) | 66.5 (25.4) | 125 (9.8) | 234 (18.4) | ||
| 60–64 | 70.6 (29.6) | 161 (11.5) | 209 (15) | 69.9 (27.6) | 126 (9) | 206 (14.8) | ||
| 65–69 | 71.2 (29.1) | 125 (11.4) | 140 (12.7) | 70.1 (26.7) | 92 (8.4) | 167 (15.2) | ||
| ≥70 | 73.8 (30) | 75 (9.3) | 102 (12.7) | 71.9 (28.4) | 66 (8.2) | 100 (12.5) | ||
| Race | ||||||||
| White | 74.4 (28.3) | 249 (7.2) | 434 (12.5) | 73.9 (27.1) | 204 (5.9) | 441 (12.7) | ||
| African American | 50.3 (25.3) | <0.001 | 349 (35) | 234 (23.4) | 52.5 (24.6) | <0.001 | 290 (29.1) | 244 (24.4) |
| Other/unknown | 72 (33.3) | 0.025 | 37 (13.8) | 29 (10.8) | 71.2 (31.9) | 0.015 | 34 (12.7) | 28 (10.4) |
| BMI, kg/m2 | <0.001 | <0.001 | ||||||
| <25 | 75.5 (31.7) | 99 (10.8) | 104 (11.4) | 74.4 (29.7) | 74 (8.1) | 119 (13) | ||
| 25–<30 | 70.8 (29.8) | 250 (10.9) | 331 (14.5) | 70.4 (27.1) | 177 (7.7) | 363 (15.9) | ||
| ≥30 | 63.1 (27.1) | 286 (18.6) | 262 (17.1) | 64.3 (24.6) | 168 (10.9) | 295 (19.2) | ||
| Month of blood draw | <0.001 | <0.001 | ||||||
| January | 65.3 (30) | 76 (18.6) | 60 (14.7) | 64.8 (28.3) | 64 (15.6) | 77 (18.8) | ||
| February | 59.1 (27.3) | 85 (20.8) | 89 (21.8) | 59.4 (26.1) | 81 (19.9) | 74 (18.1) | ||
| March | 62.3 (27.2) | 79 (18.8) | 75 (17.8) | 63.1 (25.4) | 65 (15.4) | 76 (18.1) | ||
| April | 63.2 (26.2) | 67 (17) | 72 (18.2) | 63.3 (25.3) | 56 (14.2) | 71 (18) | ||
| May | 65.7 (28.2) | 68 (17.2) | 60 (15.2) | 66.9 (25.5) | 40 (10.1) | 62 (15.7) | ||
| June | 71 (27.3) | 46 (9.7) | 68 (14.3) | 71.4 (24.7) | 20 (4.2) | 72 (15.2) | ||
| July | 74.8 (27.1) | 18 (8) | 23 (10.3) | 76.8 (24.4) | 10 (4.5) | 18 (8) | ||
| August | 83.9 (28.3) | 6 (2.5) | 19 (8.1) | 82.8 (27.5) | 8 (3.4) | 12 (5.1) | ||
| September | 80.6 (33) | 18 (5.4) | 40 (12) | 79.4 (30.7) | 15 (4.5) | 29 (8.7) | ||
| October | 77.1 (30.2) | 37 (7) | 59 (11.2) | 76 (28.2) | 27 (5.1) | 57 (10.8) | ||
| November | 71.3 (32.1) | 69 (13.4) | 69 (13.4) | 70.7 (29.9) | 55 (10.7) | 82 (15.9) | ||
| December | 63.8 (27) | 66 (16.8) | 63 (16) | 64.1 (24.5) | 50 (12.7) | 64 (16.3) | ||
↵aVitamin D values are mutually adjusted for all other variables in table before calculating categories, except for the “Total” row, which is adjusted for month only.
↵bP values are for trend, except for race, where values are for contrast with White.
↵cAll percentages are row percentages, except for the “Total” row, which is percentage of total.