Vitamin D Deficiency and Its Association with Dementia and Alzheimer's Disease in the Elderly

Background/Purpose: Emerging evidence suggests that vitamin D deficiency may have an important role in the progression of dementia and Alzheimer's disease (AD). To find the association between serum vitamin D level and dementia in the elderly. Methods: It is a retrospective case control study based on electronic medical records that included elderly patients recruited from the geriatric clinic. Patients with a diagnosis of dementia who had serum vitamin D measured before the onset of dementia were included in the study and matched with control subjects free of dementia or any other neurological disorder. Results: 325 subjects were included in this study, with mean age 77.50 +/- 7.57. The study population consisted of two groups; the dementia group which included 140 patients and the control group which included 185 subjects. Vitamin D deficiency prevalence was 54.5% (176/325) among the studied population. There was no significant statistical difference between the 2 studied groups regarding mean age, sex, comorbidities and vitamin D level, while among the demented patients there was a significant statistical difference between vitamin D deficiency and dementia subtypes being more prevalent in AD patients (72.1%) followed by vascular dementia (58.1%), mixed dementia (52.2%) and other causes of dementia (40%) respectively. Furthermore vitamin D deficiency was more prevalent among AD patients (72.1%) than control cases (49.5%) and other causes of dementia (50.6%). Conclusion: Vitamin D deficiency is prevalent among the elderly and it has been associated with AD rather than other types of dementia.