Low Vitamin D and Its Association with Cognitive Impairment and Dementia
Table 1
Summary of cross-sectional and longitudinal studies depicting association between serum 25(OH)D, cognitive impairment, and Alzheimer’s disease and other dementia.
Multivariate-adjusted linear mixed effect model used for analysis. No significant association with cognitive decline deficient versus sufficient: –0.035 (95% CI – 0.104 to 0.033) and intermediate versus sufficient: –0.029 (95% CI – 0.080 to 0.023)).
Cox proportional hazards regression (95% CI: 0.59, 1.31) in men with plasma 25(OH)D concentrations 50 compared with 0.75 n·mol/L. (95% CI: 0.63, 1.32) for the lowest compared with highest tertiles of vitamin D intake.
Multivariate analysis Vitamin D deficiency and insuffiency had double the risk of all cause dementia with 95% CI (1.21–3.71) for deficiency and 95% CI (1.17–3.36) for insufficiency
Age (30–64 years) From USA White urban adults African-Americans
MMSE CVLT TMT-B BVRT CDT DF-S and DFS-B AF
Linear regression Higher aseline serum 25OHD was linked toa slower decline in verbal fluency () Higher intake of vitamin D was associated with aslower rate of decline constructive ability (). Use of vitamin D supplements during follow-up was related to slower rate of decline in verbal fluency among older individuals.
One-way ANOVA and Pearson Chi square Vitamin D > 25n·mol/L performed better on verbal fluency (95% CI = 0.53, 4.40) and TMT-B time (95% CI = −32.86, −3.61), with higher executive function (95% CI: 0.44,2.37) These relationships persisted 10 years later in the follow-up
Linear regression Association of low vitamin D and CI found in older, more than 65 years () at cross-sectional level; no association found on follow-up
Bayesian mixed model 25(OH)D levels were negatively associated
MSE: Mini-Mental Status Examination, WFT: word fluency test, DSST: digit symbol substitution test, DWRT: delayed word recall test, and TMT: trial making test; MCI: mild cognitive impairment and RAVLT: Rey auditory verbal learning test; Consortium to Establish a Registry for Alzheimer’s Disease (CERAD), California Verbal Learning Test Second Edition (CVLT-II), verbal fluency and trail making test-B (TMT-B), delayed free recall (DFR), digit span forward and backward tests (DS-F and DS-B), Benton Visual Retention Test (BVRT), animal fluency test (AF), Brief Test of Attention (BTA), and Clock Drawing Test (CDT).