Table 3.
Multivariable regression analysis of the association of DXA areal bone mineral density (aBMD) and trabecular volumetric BMD (vBMD) with total, free, and bioavailable 25(OH)D concentrations
| Site | Measure of 25(OH)D | Black | White |
|---|---|---|---|
| Standardized regression coefficient (p value) | |||
| Lumbar spine aBMDa | Total 25(OH)D | 0.09 (0.25) | −0.04 (0.62) |
| Free 25(OH)D (polyclonal) | 0.13 (0.10) | 0.02 (0.78) | |
| Free 25(OH)D (monoclonal) | 0.15 (0.06) | 0.02 (0.73) | |
| Bioavailable 25(OH)D (polyclonal) | 0.15 (0.06) | 0.02 (0.78) | |
| Bioavailable 25(OH)D (monoclonal) | 0.17 (0.03) | 0.02 (0.76) | |
| Femoral neck aBMD | Total 25(OH)D | 0.12 (0.09) | 0.02 (0.75) |
| Free 25(OH)D (polyclonal) | 0.15 (0.03) | 0.01 (0.88) | |
| Free 25(OH)D (monoclonal) | 0.10 (0.18) | 0.08 (0.20) | |
| Bioavailable 25(OH)D (polyclonal) | 0.17 (0.02) | 0.01 (0.84) | |
| Bioavailable 25(OH)D (monoclonal) | 0.12 (0.10) | 0.08 (0.20) | |
| Total hip aBMD | Total 25(OH)D | 0.11 (0.14) | 0.005 (0.94) |
| Free 25(OH)D (polyclonal) | 0.12 (0.10) | −0.004 (0.95) | |
| Free 25(OH)D (monoclonal) | 0.08 (0.30) | 0.05 (0.50) | |
| Bioavailable 25(OH)D (polyclonal) | 0.14 (0.06) | 0.0005 (0.99) | |
| Bioavailable 25(OH)D (monoclonal) | 0.09 (0.20) | 0.05 (0.49) | |
| Ultra-distal radius aBMD | Total 25(OH)D | 0.14 (0.04) | −0.05 (0.49) |
| Free 25(OH)D (polyclonal) | 0.07 (0.29) | 0.01 (0.93) | |
| Free 25(OH)D (monoclonal) | 0.12 (0.07) | −0.01 (0.93) | |
| Bioavailable 25(OH)D (polyclonal) | 0.08 (0.23) | −0.002 (0.98) | |
| Bioavailable 25(OH)D (monoclonal) | 0.13 (0.047) | −0.01 (0.91) | |
| 1/3 radius aBMD | Total 25(OH)D | 0.10 (0.12) | 0.004 (0.96) |
| Free 25(OH)D (polyclonal) | 0.06 (0.40) | −0.002 (0.98) | |
| Free 25(OH)D (monoclonal) | 0.05 (0.47) | −0.02 (0.72) | |
| Bioavailable 25(OH)D (polyclonal) | 0.06 (0.40) | 0.0002 (1.00) | |
| Bioavailable 25(OH)D (monoclonal) | 0.05 (0.42) | −0.02 (0.75) | |
| Trabecular vBMD | Total 25(OH)D | 0.17 (0.04) | 0.03 (0.65) |
| Free 25(OH)D (polyclonal) | 0.13 (0.11) | 0.03 (0.67) | |
| Free 25(OH)D (monoclonal) | 0.16 (0.05) | 0.11 (0.12) | |
| Bioavailable 25(OH)D (polyclonal) | 0.15 (0.07) | 0.03 (0.65) | |
| Bioavailable 25(OH)D (monoclonal) | 0.17 (0.04) | 0.11 (0.11) | |
All models were adjusted for BMI, age, and sex, and the lumbar spine and 1/3 radius models also included an age-by-sex interaction term. Bolded values refer to point estimates with p<0.05
a
Log transformed to achieve normality