Table 4.
Logistic Regression Models Illustrating Odds f Memory Impairment (95% confidence intervals) by Serum 25-hydroxyvitamin D3 (25(OH)D) Levels*
| Unadjusted Model | Fully Adjusted Model† | Fully Adjusted Model Plus Medical Conditions‡ | |
| Serum 25(OH)D (nmol/L) | |||
| ≥75§ | 1.0 | 1.0 | 1.0 |
| ≥50 < 75 | 0.69 (0.52–0.92) | 0.59 (0.43–0.83) | 0.58 (0.42–0.80) |
| ≥25 < 50 | 1.45 (1.01–2.08) | 1.18 (0.78–1.81) | 1.12 (0.73–1.72) |
| <25 | 4.46 (2.07–9.59) | 3.18 (1.20–8.44) | 2.98 (1.13–7.88) |
| p for linear trend | .011 | .18 | .26 |
Notes: *Memory impairment was defined as the worst 10% of the distribution of scores. Population weights are used to adjust for the sampling design.
Adjusted for age, sex, race/ethnicity, education, season tested, current smoking status, body mass index, alcohol consumption, serum vitamin E, combined family income, impaired mobility, and physical inactivity.
Adjustment as for fully adjusted model plus medical conditions that may mediate the association between 25(OH)D and cognitive impairment (stroke, diabetes, untreated hypertension, and hypertension treated with antihypertensive drugs).
Participants with serum 25(OH)D concentrations ≥75 nmol/L served as the reference group.