TABLE 2.
Selected baseline characteristics of the study group according to ethnicity
| Characteristic | Non-Hispanic whites (n = 229) | Blacks (n = 199) | P1 |
| Serum 25-hydroxyvitamin D (nmol/L)2 | 77.1 ± 10.333 | 50.7 ± 27.4 | <0.0001 |
| Categories of serum 25-hydroxyvitamin D concentrations [n (%)] | <0.0001 | ||
| Deficient (<50 nmol/L) | 35 (15.2) | 116 (58.3) | |
| Insufficient (50 to 74.9 nmol/L) | 74 (32.3) | 50 (25.1) | |
| Sufficient (≥75 nmol/L) | 120 (52.4) | 33 (16.6) | |
| Males [n (%)] | 85 (37.1) | 51 (25.6) | 0.02 |
| Age (y) | 62.9 ± 14.0 | 58.0 ± 12.5 | 0.0002 |
| BMI (kg/m2) | 26.9 ± 5.1 | 30.3 ± 6.7 | <0.0001 |
| Dietary vitamin D intake (IU)4 | 140 ± 96 | 132 ± 96 | 0.33 |
| Supplemental vitamin D intake (IU)5 | 244 ± 316 | 224 ± 296 | 0.39 |
| Total vitamin D intake (IU)6 | 388 ± 249.2 | 352 ± 312 | 0.22 |
| Vegetarian status [n (%)] | 0.003 | ||
| Vegetarian7 | 98 (42.8) | 52 (26.1) | |
| Partial vegetarian8 | 35 (15.3) | 31 (15.6) | |
| Nonvegetarian9 | 96 (41.9) | 116 (58.3) | |
| Skin type [n (%)]10 | <0.0001 | ||
| Type I, no tan or freckles | 19 (8.3) | 1 (0.5) | |
| Type II, tans lightly | 75 (32.8) | 31 (15.6) | |
| Type III, tans moderately | 97 (42.4) | 32 (16.1) | |
| Type IV, tans darkly | 38 (16.6) | 41 (20.6) | |
| Type V or VI, skin brown or black | 0 | 85 (42.7) | |
| Unknown type | 0 | 9 (4.5) | |
| Time spent in the sun daily (min) | 89.6 ± 83.0 | 88.3 ± 86.1 | 0.73 |
| Percentage of body exposed to sunshine11 | 9.3 ± 6.5 | 8.7 ± 6.9 | 0.31 |
| Exposure factor12 | 913.9 ± 1251.3 | 952.0 ± 1467.9 | 0.62 |
Student's t test or chi-square test difference of means or percentages.
Assayed by 2-step radioimmunoassay procedure (DiaSorin, Stillwater, MN).
Mean ± SD (all such values).
Adventist Health Study-2 food-frequency questionnaire collected within 1–3 mo of blood sample. Calorie adjusted by residual method (7).
Adventist Health Study-2 food-frequency questionnaire collected within 1–3 mo of blood sample.
Sum of the population mean dietary, energy-adjusted residual, and supplemental intakes.
Ate meat and/or fish <1 time/mo.
Ate meat and fish <1 time/wk or ate meat <1 time/mo and fish ≥1 time/mo.
Ate meat and fish totaling ≥1 time/wk.
Fitzpatrick sun-reactive skin types I through VI (8).
According to Wachtel's burn chart, modified (9).
Product of time in the sun and percentage of body exposed to sunshine because only one side of body faces sun at any one time.