TABLE 1.
Characteristics of participants in the COVID-19 online survey within the Nurses’ Health Study II1
| Quintiles of predicted 25(OH)D concentrations (ng/mL) | |||||
|---|---|---|---|---|---|
| 1 (n = 7823) | 2 (n = 7836) | 3 (n = 7880) | 4 (n = 7883) | 5 (n = 7893) | |
| Median, ng/mL | 25.2 | 28.7 | 30.8 | 32.6 | 34.7 |
| Age, y | 60.8 (4.5) | 60.8 (4.6) | 60.8 (4.5) | 60.5 (4.5) | 60.5 (4.5) |
| White, % | 85.7 | 95.4 | 97.0 | 97.0 | 96.2 |
| Current postmenopausal hormone use, % | 5.7 | 10.5 | 12.7 | 19.1 | 35.9 |
| UV-B of state of residence | 126 (25.5) | 125 (25.1) | 125 (25.1) | 127 (25.3) | 133 (26.8) |
| Region, % | |||||
| West | 14.6 | 15.2 | 15.0 | 18.0 | 25.6 |
| South | 19.0 | 18.6 | 18.3 | 19.5 | 24.3 |
| Midwest | 34.2 | 33.5 | 32.3 | 31.0 | 27.0 |
| Northeast | 32.0 | 32.4 | 34.2 | 31.2 | 22.9 |
| Other | 0.2 | 0.3 | 0.2 | 0.2 | 0.2 |
| 2010 Census tract median income, US dollars | 76,664 (28,327) | 79,995 (29,567) | 83,594 (31,418) | 86,482 (33,562) | 91,774 (36,163) |
| BMI, kg/m2 | 35.6 (6.5) | 29.7 (4.5) | 26.3 (3.5) | 24.3 (3) | 22.4 (2.5) |
| Physical activity, MET-h/wk | 13.9 (20.7) | 20.8 (24.1) | 26.9 (25.3) | 34.2 (31) | 47.6 (40.3) |
| Alcohol intake, g/d | 3.1 (8.1) | 5.2 (9.8) | 7.3 (11.7) | 9.3 (11.8) | 12.8 (12.4) |
| Total vitamin D intake, IU/d | 1107 (970) | 1180 (960) | 1219 (946) | 1249 (924) | 1406 (871) |
| Dietary vitamin D intake, IU/d | 170 (101) | 183 (108) | 190 (108) | 208 (116) | 228 (116) |
| Vitamin D intake from supplements, IU/d | 902 (910) | 963 (908) | 998 (896) | 1012 (870) | 1162 (8418) |
| Alternate Healthy Eating Index | 57.5 (12.0) | 59.9 (11.8) | 62.2 (11.7) | 63.9 (11.8) | 66.4 (11.3) |
| Past smoker, % | 30.0 | 30.2 | 30.9 | 32.0 | 32.9 |
| Current smoker, % | 3.9 | 4.3 | 3.9 | 3.4 | 2.2 |
| Smoking, pack-years | 5.6 (11.3) | 5.3 (11.0) | 4.9 (10.1) | 4.6 (9.5) | 4.0 (8.3) |
| Hypertension, % | 38.7 | 27.3 | 21.9 | 17.5 | 14.3 |
| Hypercholesterolemia, % | 32.9 | 31.5 | 27.7 | 24.5 | 20.9 |
| Diabetes, % | 13.1 | 6.3 | 3.0 | 2.2 | 1.2 |
| Heart disease, % | 0.6 | 0.4 | 0.2 | 0.3 | 0.2 |
| Cancer, % | 4.3 | 3.7 | 3.7 | 3.4 | 3.0 |
| Asthma, % | 20.2 | 17.4 | 14.3 | 11.9 | 10.9 |
| Frontline health care worker, % | 29.2 | 31.0 | 29.9 | 31.0 | 29.4 |
| Vitamin D intake from foods (IU/d) | |||||
| 0–99.9 (n = 6741) | 100–199.9 (n = 17,141) | 200–299.9 (n = 9723) | 300–399.9 (n = 3560) | ≥400 (n = 2150) | |
| Median, IU/d | 75.8 | 149 | 238 | 339 | 470 |
| Age, y | 60.6 (4.5) | 60.6 (4.5) | 60.7 (4.5) | 60.8 (4.6) | 61.0 (4.5) |
| White, % | 93.4 | 94.2 | 94.8 | 95.0 | 93.8 |
| Current postmenopausal hormone use, % | 16.6 | 16.8 | 17.3 | 15.7 | 17.3 |
| UV-B of state of residence | 129 (26.5) | 128 (25.8) | 127 (25.4) | 126 (25.2) | 125 (25.2) |
| Region, % | |||||
| West | 19.2 | 17.7 | 17.0 | 17.5 | 16.3 |
| South | 21.5 | 20.5 | 19.7 | 16.9 | 16.8 |
| Midwest | 30.8 | 31.3 | 31.2 | 34.1 | 34.8 |
| Northeast | 28.2 | 30.4 | 31.8 | 31.3 | 31.8 |
| Other | 0.3 | 0.2 | 0.3 | 0.3 | 0.4 |
| 2010 Census tract median income, US dollars | 82,867 (31,874) | 83,254 (32,041) | 84,928 (32,923) | 84,534 (33,353) | 83,072 (32,073) |
| BMI, kg/m2 | 27.6 (6.3) | 27.8 (6.3) | 27.7 (6.2) | 27.4 (6.1) | 27.3 (6.4) |
| Physical activity, MET-h/wk | 27.6 (30.4) | 28.5 (31.1) | 29.5 (31.7) | 29.9 (32.2) | 28.5 (33.1) |
| Alcohol intake, g/d | 9.0 (14.6) | 8.3 (11.5) | 6.9 (9.9) | 5.4 (8.2) | 4.1 (7.0) |
| Total vitamin D intake, IU/d | 1149 (971) | 1180 (927) | 1255 (919) | 1380 (932) | 1572 (943) |
| Dietary vitamin D intake, IU/d | 71.6 (20.9) | 149 (28.2) | 242 (27.9) | 343 (28.8) | 503 (106) |
| Vitamin D intake from supplements, IU/d | 1034 (912) | 1008 (891) | 982 (873) | 1010 (892) | 1032 (872) |
| Alternate Healthy Eating Index | 61.3 (13.2) | 62.2 (12.0) | 62.5 (11.8) | 61.7 (11.7) | 60.6 (11.8) |
| Past smoker, % | 32.2 | 31.6 | 31.0 | 29.4 | 29.1 |
| Current smoker, % | 4.7 | 3.6 | 3.1 | 2.9 | 2.4 |
| Smoking, pack-years | 5.7 (11.4) | 4.9 (10.0) | 4.6 (9.7) | 4.3 (9.5) | 4.1 (8.9) |
| Hypertension, % | 23.8 | 24.9 | 23.4 | 22.5 | 21.1 |
| Hypercholesterolemia, % | 26.6 | 28.0 | 27.4 | 27.1 | 26.9 |
| Diabetes, % | 5.0 | 5.3 | 5.2 | 4.9 | 5.0 |
| Heart disease, % | 0.4 | 0.3 | 0.3 | 0.4 | 0.5 |
| Cancer, % | 3.5 | 3.5 | 3.7 | 4.2 | 3.6 |
| Asthma, % | 16.0 | 14.6 | 15.0 | 13.9 | 15.9 |
| Frontline health care worker, % | 28.9 | 30.1 | 31.0 | 30.1 | 29.6 |
| Vitamin D intake from supplements (IU/d) | |||||
| 0 (n = 4398) | 0.1–399.9 (n = 8312) | 400–999.9 (n = 8666) | 1000–1999.9 (n = 10,044) | ≥2000 (n = 7895) | |
| Median, IU/d | 0 | 38 | 607 | 1400 | 2235 |
| Age, y | 59.9 (4.5) | 60.1 (4.6) | 60.9 (4.5) | 61.1 (4.5) | 60.9 (4.4) |
| White, % | 93.8 | 93.4 | 94.1 | 94.5 | 95.3 |
| Current postmenopausal hormone use, % | 13.7 | 14.7 | 16.7 | 16.7 | 20.9 |
| UV-B of state of residence | 128 (25.3) | 127 (25.6) | 127 (25.9) | 127 (25.4) | 128 (26.5) |
| Region, % | |||||
| West | 18.0 | 18.5 | 17.1 | 16.0 | 19.5 |
| South | 20.1 | 19.0 | 19.6 | 20.3 | 20.7 |
| Midwest | 31.4 | 31.9 | 32.3 | 31.5 | 30.9 |
| Northeast | 30.1 | 30.2 | 30.8 | 32.0 | 28.9 |
| Other | 0.4 | 0.4 | 0.2 | 0.2 | 0.1 |
| 2010 Census tract median income, US dollars | 82,913 (33,103) | 83,291 (32,379) | 82,951 (32,032) | 84,163 (32,396) | 84,773 (32,128) |
| BMI, kg/m2 | 27.9 (6.4) | 27.8 (6.3) | 27.5 (6.2) | 27.4 (6.2) | 27.9 (6.4) |
| Physical activity, MET-h/wk | 27.1 (30.4) | 28 (32.9) | 29.4 (31.3) | 29.6 (31.0) | 28.5 (30.6) |
| Alcohol intake, g/d | 7.8 (11.5) | 7.8 (11.7) | 7.5 (11.3) | 7.5 (11.2) | 7.2 (11.1) |
| Total vitamin D intake, IU/d | 184 (113) | 310 (180) | 906 (253) | 1646 (433) | 2621 (529) |
| Dietary vitamin D intake, IU/d | 188 (113) | 196 (107) | 200 (113) | 197 (114) | 191 (113) |
| Vitamin D intake from supplements, IU/d | 0 (0) | 114 (134) | 686 (205) | 1407 (368) | 2357 (395) |
| Alternate Healthy Eating Index | 59.7 (12.6) | 60.2 (12.2) | 62.1 (12.9) | 63.0 (11.8) | 63.8 (11.9) |
| Past smoker, % | 32.0 | 32.1 | 31.3 | 30.0 | 31.4 |
| Current smoker, % | 5.2 | 4.6 | 3.3 | 3.0 | 2.6 |
| Smoking, pack-years | 5.6 (11.2) | 5.3 (10.6) | 4.8 (10.1) | 4.5 (9.6) | 4.7 (9.7) |
| Hypertension, % | 22.0 | 22.9 | 25.7 | 24.0 | 24.1 |
| Hypercholesterolemia, % | 22.3 | 25.7 | 28.2 | 29.1 | 29.5 |
| Diabetes, % | 4.4 | 5.2 | 5.5 | 5.2 | 5.3 |
| Heart disease, % | 0.4 | 0.5 | 0.4 | 0.3 | 0.2 |
| Cancer, % | 3.2 | 3.3 | 3.7 | 3.9 | 3.7 |
| Asthma, % | 13.0 | 13.0 | 14.3 | 15.3 | 18.4 |
| Frontline healthcare worker, % | 31.0 | 31.1 | 29.4 | 29.5 | 29.8 |
1
Values are means (SD) or percentages standardized to the distribution of age, with the exception of age itself. COVID-19, coronavirus disease 2019; MET, metabolic equivalent of task; 25(OH)D, 25-hydroxyvitamin.