Table 3.
Serum vitamin D concentrations for all confounding variables of study population: the Third National Health and Nutrition Examination Survey
| Characteristic | Serum vitamin D1 (nmol/L) |
|---|---|
| Sex | |
| Men (n = 3652) | 80.5 ± 1.3 |
| Women (n = 4318) | 75.7 ± 1.4 |
| Race-ethnicity | |
| Non-Hispanic white (n = 2281) | 86.5 ± 1.4 |
| Non-Hispanic black (n = 2634) | 48.5 ± 1.2 |
| Mexican American/Hispanic (n = 2711) | 65.3 ± 1.2 |
| Other (n = 344) | 63.0 ± 1.5 |
| Geographical location | |
| Northeast (n = 958) | 85.0 ± 2.3 |
| Midwest (n = 1482) | 86.3 ± 3.3 |
| South (n = 3460) | 71.8 ± 1.7 |
| West (n = 2070) | 72.6 ± 1.8 |
| Urbanization | |
| Urban living (n = 4135) | 72.5 ± 1.3 |
| Rural living (n = 3795) | 83.6 ± 2.0 |
| Supplement use 2 | |
| Yes (n = 2262) | 81.0 ± 1.4 |
| No (n = 4992) | 75.9 ± 1.4 |
| Prescription medicine use 3 | |
| Yes (n = 1845) | 79.3 ± 1.7 |
| No (n = 5409) | 77.2 ± 1.2 |
| Poverty income ratio 4 | |
| <1.0 (below poverty) (n = 2170) | 69.9 ± 1.4 |
| 2.0-<3.0 (low-middle income) (n = 2058) | 76.4 ± 1.7 |
| 3.0-<4.0 (high-middle income) (n = 2267) | 79.3 ± 1.4 |
| ≥4.0 (high income) (n = 818) | 84.5 ± 2.1 |
| Body mass index (Kg/m2) | |
| Underweight (<18.5) (n = 277) | 84.7 ± 3.5 |
| Normal weight (18.5-<25) (n = 3911) | 82.4 ± 1.3 |
| Overweight (25-<30) (n = 2179) | 76.3 ± 1.5 |
| Obese (≥30) (n = 1583) | 65.6 ± 1.5 |
| Serum creatinine | |
| <70 μmol/L (n = 446) | 70.2 ± 3.0 |
| 70-124 μmol/L (n = 7068) | 78.6 ± 1.2 |
| >124 μmol/L (n = 302) | 72.2 ± 2.7 |
1 Values are means ± standard error of mean
2 Vitamin/mineral supplement use 1 month prior to the survey
3 Prescription medicine use 1 month prior to the survey
4 The ratio of a family's income to their appropriate threshold income