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The effect of vitamins on cognitive function in middle‐aged and older adults without dementia
Author(s) -
Suh Seung Wan,
Kim Hye Sung,
Han Ji Hyun,
Bae Jong Bin,
Oh Dae Jong,
Han Ji Won,
Kim Ki Woong
Publication year - 2020
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1002/alz.043645
Subject(s) - medicine , randomized controlled trial , dementia , meta analysis , strictly standardized mean difference , cochrane library , vitamin e , cinahl , vitamin , cognition , antioxidant , pediatrics , gerontology , psychiatry , psychological intervention , biology , biochemistry , disease
Background Evidence suggests that vitamins might have a beneficial effect for cognition. The current systematic review aims to investigate the effect of B vitamins, antioxidant vitamins, and vitamin D on cognitive function in the non‐demented middle‐aged or older people. Method Randomized, or quasi‐randomized clinical trials comparing vitamin supplementation with a control group were included in the standard inverse‐variance random‐effects meta‐analyses. We searched PubMed/MEDLINE, EMBASE, CINAHL, PsycINFO, Cochrane Library databases for articles until November 2019, and used Risk of Bias tool to evaluate methodological quality of them. Result A total of twenty‐three studies for B vitamins (n = 22 – 1,053), five studies for antioxidant vitamins (n = 185 – 5,226), and six studies for vitamin D (n = 55 – 4,122) were included in the meta‐analyses. We found that B vitamins had a beneficial effect on global cognitive function (Standardized mean difference [SMD] ‐0.23, 95% CI ‐0.35 to ‐0.10) which effect remained significant over 3‐11 months (SMD ‐0.80, 95% CI ‐1.03 to ‐0.56) and 12 or more months (SMD ‐0.12, 95% CI ‐0.22 to ‐0.01) of supplementation, for those from North America / Europe / Australia (SMD ‐0.07, 95% CI ‐0.11 to ‐0.03), and for those with mild cognitive impairment (SMD ‐0.51, 95% CI ‐0.81 to ‐0.22). B vitamins also showed a significant benefit on episodic memory (SMD ‐0.23, 95% CI ‐0.35 to ‐0.10). Antioxidant and vitamin D revealed no significant benefit on cognitive function compared to control groups. Conclusion Our findings indicated that B vitamins might have a therapeutic effect on global cognitive function and episodic memory domain. More life‐span studies are warranted to identify the most effective timing and duration of the vitamin supplementation.