TABLE 2.
Associations of vitamin D deficiency and insufficiency with all-cause dementia, Alzheimer’s disease, and vascular dementia in 269,229 UK Biobank participants
| Dementia outcomes | Vitamin D deficiency (n = 49,210) |
Vitamin D insufficiency (n = 91,463) |
Vitamin D sufficiency (n = 128,556) |
|||
|---|---|---|---|---|---|---|
| Ncases (%) | HR (95% CI)6 | Ncases (%) | HR (95% CI)6 | Ncases (%) | HR (95% CI) | |
| All-cause dementia | 1538 (3.1) | 2422 (2.7) | 3127 (2.4) | |||
| Model 11 | 1.58 (1.48, 1.68) | 1.18 (1.12, 1.25) | Ref | |||
| Model 22 | 1.49 (1.39, 1.59) | 1.16 (1.10, 1.23) | Ref | |||
| Model 33 | 1.37 (1.28, 1.47) | 1.12 (1.06, 1.19) | Ref | |||
| Model 44 | 1.36 (1.26, 1.46) | 1.12 (1.06, 1.18) | Ref | |||
| Model 55 | 1.25 (1.16, 1.34) | 1.11 (1.05, 1.18) | Ref | |||
| Alzheimer’s disease | 726 (1.5) | 1237 (1.4) | 1653 (1.3) | |||
| Model 11 | 1.24 (1.13, 1.36) | 1.09 (1.01, 1.17) | Ref | |||
| Model 22 | 1.21 (1.10, 1.33) | 1.08 (1.00, 1.17) | Ref | |||
| Model 33 | 1.23 (1.11, 1.35) | 1.09 (1.01, 1.18) | Ref | |||
| Model 44 | 1.25 (1.13, 1.39) | 1.11 (1.03, 1.20) | Ref | |||
| Model 55 | 1.19 (1.07, 1.31) | 1.10 (1.02, 1.19) | Ref | |||
| Vascular dementia | 413 (0.8) | 633 (0.7) | 769 (0.6) | |||
| Model 11 | 1.68 (1.47, 1.91) | 1.26 (1.13, 1.40) | Ref | |||
| Model 22 | 1.56 (1.36, 1.77) | 1.24 (1.11, 1.38) | Ref | |||
| Model 33 | 1.44 (1.26, 1.66) | 1.20 (1.07, 1.34) | Ref | |||
| Model 44 | 1.37 (1.19, 1.57) | 1.16 (1.04, 1.30) | Ref | |||
| Model 55 | 1.24 (1.08, 1.43) | 1.15 (1.03, 1.29) | Ref | |||
The covariates were modeled as continuous or categorical variables as shown in Supplemental Table 1, which displays their distributions according to the vitamin D status groups. 6 HRs with 95% CIs were derived from Cox proportional hazards models.
Abbreviations: CI: confidence interval, HR: hazard ratio, Ref: reference
Cox proportional hazards model 1: Age, sex, skin color, latitude of study center and calendar month of attending the assessment center.
Cox proportional hazards model 2: Model 1 variables plus socioeconomic factors (education, indices of multiple deprivation, no of individuals in household, and household income).
Cox proportional hazards model 3: Model 2 variables plus lifestyle factors (smoking, alcohol consumption, physical activity, frequency of visiting friends/family and consumption of oily fish, cereal, processed meat, milk, bread, and spread), and vitamin D specific factors (time spent outdoors in summer and winter, ease of skin tanning, use of sunscreen/UV protection, and solarium/sunlamp use).
Cox proportional hazards model 4: Model 3 variables plus weight variables (body mass index and waist circumference).
Cox proportional hazards model 5: Model 4 variables plus diseases and disease symptoms (diabetes, stroke, coronary artery disease, chronic obstructive pulmonary disease, osteoporosis, arthritis, gout, Parkinson, depressed mood, and tiredness/lethargy), biomarkers (estimated glomerular filtration rate, HbA1c, HDL cholesterol, systolic blood pressure, diastolic blood pressure, C-reactive protein, forced expiratory volume in 1 s, and hand grip strength), general health status (no. of drugs, no. of chronic diseases, disability, and general self-rated health), and Apolipoprotein E ε4 status.