Table 1.
Main characteristics of eligible studies for the analysis of vitamin D deficiency and risk of PD.
| References | Year | Country | Study Type | Number of Participants | Average Age (years) | OR (95% CI) * | Adjustments | ||
|---|---|---|---|---|---|---|---|---|---|
| PD | Control | PD | Control | ||||||
| Evatt [15] | 2008 | USA | cohort | 100 | 99 | 65.4 | 65.7 | 2.28 (1.03, 5.03) (deficient) 1.51 (0.91, 2.50) (insufficient) |
age, sex, race, symptom duration, and sampling season |
| Ding [16] | 2013 | USA | cross-sectional and case-control | 388 | 283 | 65.7 ± 9.6 | 8.0 ± 10.4 | 1.91 (1.18, 3.07) (deficient) 1.19 (0.90, 1.57) (insufficient) |
age, sex, race, and vitamin D supplementation |
| Wang [17] | 2015 | USA | case-control | 478 | 431 | 64 ± 12 | 70 ± 8 | 2.12 (1.57, 2.88) (deficient) 1.31 (1.06, 1.62) (insufficient) |
age, sex, and sampling season |
* To unify the data OR and 95% CI were calculated using Stata according to the corresponding events and total numbers in PD and controls groups of eligible studies.