Background and objectives. Alzheimer’s dementia (AD) is the most common type of dementia and is classified as a neurodegenerative disease, accounting for at least two-thirds of cases in individuals aged 65 years and older. In recent years, several studies have discussed the association between vitamin D serum deficits and the risk of developing AD. This study aims to investigate the correlation between vitamin D serum deficits and AD risk. Materials and methods. This meta-analysis followed PRISMA guidelines to assess vitamin D serum deficits as a risk factor for AD. We included five studies identified through comprehensive searches in PubMed, Google Scholar, ScienceDirect, Wiley Online Library, and ResearchGate. Risk of bias was assessed using the ROBINS-E tool, and meta-analysis was conducted using Review Manager 5.4.1. Results. Four prospective cohort studies and one cross-sectional study were included. The odds ratios (ORs) for AD were 1.40 (95% CI: 1.01–1.94; p = 0.05) for total vitamin D serum deficits (<50 nmol/L), 1.47 (95% CI: 1.07–2.02; p = 0.02) for vitamin D insufficiency (25–<50 nmol/L), and 2.73 (95% CI: 1.72–4.34; p < 0.0001) for vitamin D deficiency (<25 nmol/L). Conclusions. This study confirms a significant correlation between AD and vitamin D serum deficits, with vitamin D deficiency showing a stronger association with AD risk than vitamin D insufficiency. These findings suggest that lower vitamin D serum levels may be associated with an increased risk of developing AD.
' et al. (Mon,) studied this question.