Vitamin D status and measures of cognitive function in healthy older European adults

Abstract

Background/Objectives: Data from human studies that have investigated the association between vitamin D status and cognitive function in elderly adults are conflicting. The objective of this study was to assess vitamin D status (reflected by serum 25-hydroxyvitamin D (25(OH)D)) in older European subjects (n ¼ 387; aged 55-87 years) and examine its association with measures of cognitive function. Subjects/Methods: Serum 25(OH)D was assessed using enzyme-linked immunosorbent assay, whereas measures of cognitive function were assessed using a comprehensive Cambridge Neuropsychological Testing Automated Battery (CANTAB). Results: In all, 12, 36 and 64% of subjects had serum 25(OH)D concentrations o30, o50 and o80 nmol/l, respectively, throughout the year. Serum 25(OH)D was significantly and inversely correlated with four assessments within the spatial working memory (SWM) test parameter (SWM between errors (r ¼ À0.166; P ¼ 0.003); SWM between errors 8 boxes (r ¼ À0.134; P ¼ 0.038); SWM strategy (r ¼ À0.246; Po0.0001); and SWM total errors (r ¼ À0.174; Po0.003)). When subjects were stratified on the basis of tertiles (T) of serum 25(OH)D (o47.6 (T 1 ); 47.6-85.8 (T 2 ); and 485.8 (T 3 ) nmol/l), fewer errors in SWM test scores occurred in subjects in the third T when compared with the first T (Po0.05-0.084). Stratification by sex showed that these differences between tertiles strengthened (Po0.001-0.043) in the females, but the differences were not significant (P40.6) in males. Conclusions: Vitamin D insufficiency, but not deficiency, is widespread in the older population of several European countries. Low vitamin D status was associated with a reduced capacity for SWM, particularly in women.

The Effects of Vitamin D Insufficiency and Seasonal Decrease on Cognition

“…functioning are the cognitive domains most associated with vitamin d status. thus, our results support and extend those of previous findings in studies using lower vitamin d cut-off values and different population groups, including older adults 7,8 , europeans 6,8 , and men 6 . Specifically, among elders (65-99 yrs) enrolled in the naMe Study, vitamin d levels >50 nmol/l were associated with better performance on several tasks of executive functioning/attention, even after controlling for several potential confounders.…”

“…Similarly, among middle-aged and older (40-79 yrs) european men as part of the european Male aging Study 6 , those with low vitamin d levels (<35 nmol/l) performed worse on digit symbol substitution, after correcting for multiple variables. in healthy european adults (55-87 yrs) enrolled in the Zenith study 8 , vitamin d levels were significantly correlated with performance on the CantaB® Spatial Working Memory task, as we found in our cross-sectional analysis in winter. While reverse causation (i.e., that cognitive impairment leads to low vitamin d levels due to lack of outdoor activity) has been questioned regarding cross-sectional dementia case control results, it seems less likely in this relatively healthy sample with no overt dementia or physical impairment.…”

“…question [5][6][7][8] . Because of heterogeneity in methodology, particularly specific tests used, these studies were not included in the recent meta-analyses.…”

Vitamin D Deficiency, Cognitive Impairment and Dementia: A Systematic Review and Meta-Analysis

“…In another population-based study with 752 women aged ≥75 years from the 'Epidemiologie de l'Osteoporose' (EPIDOS) cohort, after adjustment for multiple confounders, an association of deficient vitamin D concentration (<10 ng/ml) with cognitive impairment assessed by Pfeiffer Short Portable Mental State Questionnaire was reported (OR 1.99; 95% CI 1.13-3.52) [27]. An Irish multicenter study among 387 elderly healthy Etgen/Sander/Bickel/Sander/Förstl participants reported an association of vitamin insufficiency and impaired spatial working memory, especially in women [28]. Annweiler et al [29] found in 288 older patients of a French geriatric acute care unit a significant association between severe vitamin D deficiency (<10 ng/ml) and moderately severe to severe dementia (OR 2.57; 95% CI 1.05-6.27).…”

Serum 25-Hydroxyvitamin D and Cognitive Decline: A Longitudinal Study among Non-Demented Older Adults

“…Low levels of 25(OH)D have been associated with cognitive impairment among women in several cross-sectional studies [6,7], and among men in a large study including 3,133 non-institutionalized males [8]. Among women and men receiving home services, low levels of 25(OH)D were associated with dementia and cerebrovascular pathology [9], and among older patients at a memory clinic, hypovitaminosis D was associated with executive dysfunction [10].…”