Table 1. NHANES III study population characteristics.
Unweighted descriptive statistics are shown for basic demographic variables (sex, age, and body mass index) as well as the two measures of vitamin K levels. Sample sizes shown are for participants with dietary vitamin K levels available. Serum vitamin K levels were only measured in non-Hispanic white women ages 6–29 years in Phase 2 of NHANES III (n=348).
| Non-Hispanic whites (n=2,344) | Non-Hispanic blacks (n=1,675) | Mexican Americans (n=1,706) | |
|---|---|---|---|
| % female | 61 | 58 | 50 |
| Mean (±SD) age in years | 53.46 (20.32) | 40.79 (16.71) | 41.15 (17.42) |
| Mean (±SD) body mass index (kg/m2) | 26.66 (5.6) | 27.3 (369.6) | 27.1 (422.6) |
| Mean (±SD) ln(dietary vitamin K) (mcg) | 4.05 (0.97) | 4.02 (1.29) | 3.79 (0.99) |
| Mean (±SD) ln(serum vitamin K) (mg/dl) | −1.30 (0.79) | - | - |
Abbreviations: standard deviation (SD), natural log (ln).