Diet, supplemental micronutrient intake and risk of test-confirmed COVID-19: crude and minimally adjusted ORs
| Number (%) with incident test-confirmed COVID-19 | Total number | Crude OR (95% CI) | Minimally adjusted OR (95% CI)* | ||
| Diet | |||||
| Dietary restrictions | None | 419 (2.9) | 15 227 | 1.00 | 1.00 |
| Vegetarian† | 22 (3.2) | 1.11 (0.72 to 1.72) | 0.89 (0.57 to 1.40) | ||
| Vegan‡ | 5 (2.2) | 0.75 (0.31 to 1.83) | 0.60 (0.24 to 1.49) | ||
| Number of portions of fruit, vegetables and salad intake per day in week prior to questionnaire completion, quartiles | Q1 | 78 (3.5) | 15 188 | 1.00 | 1.00 |
| Q2 | 158 (3.1) | 0.88 (0.67 to 1.17) | 0.90 (0.68 to 1.20) | ||
| Q3 | 87 (3.0) | 0.85 (0.62 to 1.16) | 0.89 (0.64 to 1.22) | ||
| Q4 | 120 (2.4) | 0.66 (0.49 to 0.88) | 0.73 (0.54 to 0.99) | ||
| Number of portions of dairy products per day in week prior to questionnaire completion | 0–1 | 114 (2.8) | 15 183 | 1.00 | 1.00 |
| 2 | 142 (3.2) | 1.15 (0.90 to 1.48) | 1.18 (0.91 to 1.53) | ||
| 3–5 | 99 (2.7) | 0.96 (0.73 to 1.27) | 1.06 (0.80 to 1.41) | ||
| ≥6 | 91 (2.9) | 1.03 (0.78 to 1.37) | 1.24 (0.93 to 1.65) | ||
| Total number of portions of fish (oily or white) intake in the week prior to questionnaire completion | Q1 | 94 (3.8) | 15 213 | 1.00 | 1.00 |
| Q2 | 79 (3.2) | 0.85 (0.63 to 1.15) | 0.99 (0.73 to 1.36) | ||
| Q3 | 111 (2.7) | 0.71 (0.53 to 0.93) | 0.88 (0.66 to 1.18) | ||
| Q4 | 162 (2.6) | 0.70 (0.54 to 0.90) | 0.95 (0.72 to 1.25) | ||
| Portions of oily fish intake in the week prior to questionnaire completion | 0 | 210 (3.7) | 15 220 | 1.00 | 1.00 |
| 1 | 133 (2.7) | 0.72 (0.58 to 0.90) | 0.86 (0.69 to 1.08) | ||
| 2 | 71 (2.4) | 0.64 (0.49 to 0.85) | 0.80 (0.60 to 1.06) | ||
| ≥3 | 32 (2.1) | 0.57 (0.39 to 0.83) | 0.76 (0.52 to 1.13) | ||
| Portions of white fish intake in the week prior to questionnaire completion | 0 | 131 (3.3) | 15 216 | 1.00 | 1.00 |
| 1 | 170 (2.8) | 0.83 (0.66 to 1.04) | 0.99 (0.78 to 1.26) | ||
| 2 | 92 (2.6) | 0.76 (0.58 to 1.00) | 0.95 (0.72 to 1.26) | ||
| ≥3 | 53 (3.3) | 0.98 (0.71 to 1.35) | 1.16 (0.83 to 1.61) | ||
| Number of cups of non-alcoholic fluids per day in the week prior to questionnaire completion, quartiles | Q1 | 104 (3.0) | 15 177 | 1.00 | 1.00 |
| Q2 | 75 (2.9) | 0.98 (0.73 to 1.32) | 1.03 (0.76 to 1.41) | ||
| Q3 | 116 (2.5) | 0.84 (0.64 to 1.10) | 0.81 (0.62 to 1.07) | ||
| Q4 | 149 (3.4) | 1.14 (0.88 to 1.47) | 0.99 (0.76 to 1.29) | ||
| Micronutrient supplement use | |||||
| Multivitamin supplement | No | 331 (2.7) | 15 227 | 1.00 | 1.00 |
| Yes | 115 (3.6) | 1.33 (1.07 to 1.65) | 1.12 (0.89 to 1.40) | ||
| Vitamin A supplement | No | 445 (2.9) | 15 227 | 1.00 | 1.00 |
| Yes | 1 (1.1) | 0.38 (0.05 to 2.73) | 0.43 (0.06 to 3.15) | ||
| Vitamin C supplement | No | 397 (2.9) | 15 227 | 1.00 | 1.00 |
| Yes | 49 (3.1) | 1.09 (0.80 to 1.47) | 1.03 (0.76 to 1.41) | ||
| Vitamin D supplement | No | 305 (3.2) | 15 227 | 1.00 | 1.00 |
| Yes | 141 (2.5) | 0.80 (0.65 to 0.98) | 0.80 (0.65 to 0.99) | ||
| Zinc supplement | No | 425 (2.9) | 15 227 | 1.00 | 1.00 |
| Yes | 21 (2.8) | 0.97 (0.62 to 1.51) | 0.93 (0.58 to 1.46) | ||
| Iron supplement | No | 423 (2.9) | 15 227 | 1.00 | 1.00 |
| Yes | 23 (4.6) | 1.63 (1.06 to 2.51) | 1.27 (0.82 to 1.98) | ||
| Probiotic supplement | No | 426 (3.0) | 15 227 | 1.00 | 1.00 |
| Yes | 20 (2.2) | 0.72 (0.46 to 1.13) | 0.69 (0.44 to 1.10) | ||
| Fish oil, krill oil or other omega-3 supplements | No | 400 (3.0) | 15 227 | 1.00 | 1.00 |
| Yes | 46 (2.7) | 0.91 (0.67 to 1.25) | 0.98 (0.71 to 1.35) | ||
| Cod liver oil supplement | No | 409 (2.9) | 15 227 | 1.00 | 1.00 |
| Yes | 37 (3.0) | 1.03 (0.73 to 1.45) | 1.29 (0.91 to 1.84) | ||
| Garlic or garlic powder (allicin) supplement | No | 439 (2.9) | 15 227 | 1.00 | 1.00 |
| Yes | 7 (2.3) | 0.77 (0.36 to 1.63) | 0.93 (0.43 to 2.02) | ||
| Selenium supplement | No | 445 (3.0) | 15 227 | 1.00 | 1.00 |
| Yes | 1 (0.6) | 0.21 (0.03 to 1.47) | 0.20 (0.03 to 1.46) | ||
Minimally adjusted ORs (95% CI) with a p value of <0.10 are emboldened.
*Adjusted for age, sex, duration of participation and test frequency.
†Defined as excluding meat and fish, but not eggs or cow’s milk, from the diet.
‡Defined as excluding meat, fish, eggs and cow’s milk from the diet.