Demographic characteristics of the study population
| UK (n=372 720) | USA (n=45 757) | SE (n=27 373) | ||||
| Supplement users | Supplement users | Supplement users | ||||
| Yes | No | Yes | No | Yes | No | |
| N (%) | 175 652 (47.1%) | 197 068 (52.9%) | 32 314 (70.6%) | 13 443 (29.4%) | 13 422 (49%) | 13 951 (51%) |
| SARS-CoV-2 positive, n (%) | 10 508 (6%) | 13 013 (6.6%) | 2002 (6.2%) | 1211 (9%) | 1806 (13.5%) | 2206 (15.8%) |
| Females, n (%) | 123 462 (70.3%) | 125 651 (63.8%) | 22 817 (70.6%) | 8210 (61.1%) | 9694 (72.2%) | 9088 (65.1%) |
| White, n (%) | 163 479 (93.1%) | 188 030 (95.4%) | 28 143 (87.1%) | 11 757 (87.5%) | 13 411 (99.9%) | 13 943 (99.9%) |
| Current smoker, n (%) | 6004 (3.4%) | 10 773 (5.5%) | 1252 (3.9%) | 924 (6.9%) | 735 (5.5%) | 795 (5.7%) |
| Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | |
| Age, years | 49.57 (14.2) | 46.26 (14.4) | 56.24 (15.2) | 47.8 (16.0) | 49.0 (13.0) | 46.63 (12.9) |
| BMI, kg/m2 | 26.59 (5.6) | 27.04 (5.7) | 27.27 (5.9) | 27.21 (6) | 26.1 (4.8) | 26 (4.7) |
| IMD, median (IQR) | 7 (5) | 6 (5) | – | – | – | – |
| DQI, median (IQR) | 11 (3) | 11 (3) | – | – | – | – |
| N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | |
| Omega-3 | 39 263 (22.4%) | – | 8663 (26.8%) | – | 3039 (22.6%) | – |
| Probiotics | 20 449 (11.6%) | – | 7268 (22.5%) | – | 1715 (12.8%) | – |
| Garlic | 7235 (4.1%) | – | 1137 (3.5%) | – | 941 (7%) | – |
| Multivitamins | 77 034 (43.9%) | – | 18 843 (58.3%) | – | 5496 (41%) | – |
| Vitamin D | 86 190 (49.1%) | – | 19 444 (60.2%) | – | 6722 (50.1%) | – |
| Vitamin C | 46 755 (26.6%) | – | 10 136 (31.4%) | – | 4045 (30.1%) | – |
| Zinc | 21 776 (12.4%) | – | 4330 (13.4%) | – | 2394 (17.8%) | – |
| Type 2 diabetes | 5047 (2.9%) | 4842 (2.5%) | 1787 (5.5%) | 437 (3.3%) | 331 (2.5%%) | 251 (1.8%%) |
| Cancer | 2178 (1.2%) | 1902 (1%) | 977 (3%) | 217 (1.6%) | 157 (1.2%) | 130 (0.9%) |
| Asthma | 27 146 (15.5%) | 26 020 (13.2%) | 5015 (15.5%) | 1788 (13.3%) | 2039 (15.2%) | 1673 (12%) |
| Heart disease | 5708 (3.3%) | 5278 (2.7%) | 2388 (7.4%) | 590 (4.4%) | 654 (4.9%) | 592 (4.2%) |
| Eczema | 22 896 (13%) | 23 454 (11.9%) | 3423 (10.6%) | 1346 (10%) | 1768 (13.2%) | 1779 (12.8%) |
| Hay fever | 79 024 (45%) | 80 114 (40.7%) | 17 000 (52.6%) | 6256 (46.5%) | 5497 (41%) | 5256 (37.7%) |
| Kidney disease | 1702 (1%) | 1542 (0.8%) | 630 (2%) | 143 (1.1%) | 117 (0.9%) | 102 (0.7%) |
| Lung disease | 24 651 (14%) | 22 924 (11.6%) | 4331 (13.4%) | 1329 (9.9%) | 1894 (14.1%) | 1488 (10.1%) |
Self-reported comorbidities were not asked at sign-up and therefore not reported by all subjects.
BMI, body mass index; DQI, Diet Quality Score; IMD, index of multiple deprivation; SE, Sweden.