Table 1. Characteristics of the 1447 included older adults by 25(OH)D quartiles.
| 25(OH)D, N (%) | ||||||
|---|---|---|---|---|---|---|
| Q1 (3.0–8.7 ng/mL) 360 (24.9) |
Q2 (8.8–14.3 ng/mL) 364 (25.2) |
Q3 (14.4–22.9 ng/mL) 361 (24.9) |
Q4 (23.0–178.1 ng/mL) 362 (25.0) |
p-value | ||
| Sex | ||||||
| Women | 246 (68.3) | 221 (60.7) | 186 (51.5) | 184 (50.8) | <0.001a | |
| Men | 114 (31.7) | 143 (39.3) | 175 (48.5) | 178 (49.2) | ||
| Age (years) | ||||||
| 65–75 | 127 (35.3) | 214 (58.8) | 238 (65.9) | 247 (68.2) | <0.001a | |
| >75 | 233 (64.7) | 150 (41.2) | 123 (34.1) | 115 (31.8) | ||
| Education level | ||||||
| Without schooling | 84 (23.3) | 70 (19.2) | 25 (6.9) | 26 (7.2) | <0.001a | |
| 1–4 years | 242 (67.2) | 243 (66.8) | 262 (72.6) | 245 (67.7) | ||
| 5–12 years | 24 (6.7) | 39 (10.7) | 56 (15.5) | 64 (17.7) | ||
| >12 years | 10 (2.8) | 12 (3.3) | 18 (5.0) | 27 (7.5) | ||
| Smoking status | ||||||
| Non-smoker | 345 (95.8) | 346 (95.1) | 343 (95.0) | 347 (95.9) | 0.909a | |
| Smoker | 15 (4.2) | 18 (4.9) | 18 (5.0) | 15 (4.1) | ||
| Alcohol consumption | ||||||
| None | 222 (61.7) | 194 (53.3) | 160 (44.3) | 129 (35.6) | <0.001a | |
| Moderate (W: ≤1/day; M: ≤2/day) | 117 (32.5) | 136 (37.4) | 156 (43.2) | 188 (51.9) | ||
| Excessive (W: >1/day; M: >2/day) | 21 (5.8) | 34 (9.3) | 45 (12.5) | 45 (12.4) | ||
| Cognitive function (MMSE) | ||||||
| Not impaired | 324 (90.0) | 345 (94.8) | 334 (92.5) | 352 (97.2) | 0.001a | |
| Impaired | 36 (10.0) | 19 (5.2) | 27 (7.5) | 10 (2.8) | ||
| Frailty status | ||||||
| Normal | 30 (8.3) | 84 (23.1) | 111 (30.7) | 127 (35.1) | <0.001a | |
| Pre-frailty | 195 (54.2) | 198 (54.4) | 205 (56.8) | 187 (51.7) | ||
| Frailty | 135 (37.5) | 82 (22.5) | 45 (12.5) | 48 (13.3) | ||
| BMI categories | ||||||
| Underweight | 14 (3.9) | 8 (2.2) | 6 (1.7) | 21 (5.8) | <0.001a | |
| Normal weight | 41 (11.4) | 37 (10.2) | 60 (16.6) | 52 (14.4) | ||
| Pre-obesity | 142 (39.4) | 157 (43.1) | 167 (46.3) | 176 (48.6) | ||
| Obesity | 163 (45.3) | 162 (44.5) | 128 (35.5) | 113 (31.2) | ||
| WC (cm), median (IQR)† | 102.0 (17.1) | 101.2 (14.4) | 98.0 (14.5) | 96.6 (16.3) | <0.001b | |
| WC † | ||||||
| W: ≤80 cm; M: ≤94 cm | 27 (7.6) | 34 (9.4) | 51 (14.2) | 67 (18.6) | <0.001a | |
| W: 81–88 cm; M: 95–102 cm | 49 (13.7) | 61 (16.9) | 89 (24.8) | 103 (28.6) | ||
| W: >88 cm; M: >102 cm | 281 (78.7) | 266 (73.7) | 219 (61.0) | 190 (52.8) | ||
| BRI, median (IQR)† | 7.1 (2.6) | 6.4 (2.3) | 5.8 (2.1) | 5.6 (2.3) | <0.001b | |
| ABSI (m11/6·kg-2/3), mean (SD)† | 0.086 (0.005) | 0.084 (0.005) | 0.083 (0.005) | 0.083 (0.006) | <0.001c | |
| 25(OH)D (ng/mL), median (IQR) | 5.6 (3.0) | 11.5 (2.9) | 17.9 (3.6) | 29.2 (8.7) | <0.001b | |
| Skin phenotype | ||||||
| Red-haired with freckles or fair-haired people | 61 (16.9) | 85 (23.4) | 91 (25.2) | 65 (18.0) | 0.014a | |
| Dark-haired or Latin people | 277 (76.9) | 257 (70.6) | 251 (69.5) | 286 (79.0) | ||
| Arab, Asian or Black people | 22 (6.1) | 22 (6.0) | 19 (5.3) | 11 (3.0) | ||
| Season of blood collection | ||||||
| Spring/Summer | 91 (25.3) | 167 (45.9) | 208 (57.6) | 236 (65.2) | <0.001a | |
| Autumn/Winter | 269 (74.7) | 197 (54.1) | 153 (42.4) | 126 (34.8) | ||
| Vitamin D supplementation | ||||||
| No use | 290 (80.6) | 315 (86.5) | 319 (88.4) | 294 (81.2) | <0.001a | |
| Use of vitamin D supplements | 5 (1.4) | 10 (2.7) | 15 (4.2) | 47 (13.0) | ||
| Unknown use or composition | 65 (18.1) | 39 (10.7) | 27 (7.5) | 21 (5.8) | ||
W: Women; M: Men; MMSE: Mini Mental State Examination; BMI: Body mass index; WC: Waist circumference; BRI: Body roundness index; ABSI: Body shape index; SD: Standard Deviation; IQR: Interquartile range. Column percentages may not add to 100% due to rounding.
a Chi-square test;
b Kruskal-Wallis test;
c ANOVA test
†Missing data in 10 individuals (0.7%)