Dementia is associated with low vitamin D (most meta-analyses agree) July 2018

Quality assessment of systematic reviews of vitamin D, cognition and dementia.

BJPsych Open. 2018 Jul;4(4):238-249. doi: 10.1192/bjo.2018.32.
Aghajafari F1, Pond D2, Catzikiris N3, Cameron I4.

  • 1 Assistant Professor, Dept of Family Medicine, Cumming School of Medicine, U. of Calgary Sunridge Family Medicine Teaching Centre, Canada.
  • 2 Professor and Head of Department of Family Medicine, University of Newcastle, Australia.
  • 3 Research Assistant, School of Medicine and Public Health, Faculty of Medicine, The University of Newcastle, Australia.
  • 4 Professor, Northern Clinical School, Rehabilitation Studies Unit, Sydney Medical School, The University of Sydney, Australia.

Items in both categories Cognitive and Meta-analysis are listed here:

Alzheimers-Cognition - Overview has the following summary

BACKGROUND: There is conflicting evidence regarding the association of vitamin D with cognition performance and dementia.

Aims We aimed to summarise the evidence on the association of vitamin D with cognitive performance, dementia and Alzheimer disease through a qualitative assessment of available systematic reviews and meta-analyses.

METHOD: We conducted an overview of the systematic reviews of all study types with or without meta-analyses on vitamin D and either Alzheimer disease, dementia or cognitive performance up to June 2017.

Eleven systematic reviews were identified, nine of which were meta-analyses with substantial heterogeneity, differing statistical methods, variable methodological quality and quality of data abstraction. A Measurement Tool to Assess Systematic Reviews checklist scores ranged from 4 to 10 out of 11, with seven reviews of 'moderate' and four of 'high' methodological quality.
Out of six meta-analyses on the association between low serum concentration of 25-hydroxyvitamin D and risk of dementia, five showed a positive association. Results of meta-analyses on the association between low serum concentration of 25-hydroxyvitamin D and memory function tests showed conflicting results.

This systematic evaluation of available systematic reviews provided a clearer understanding of the potential link between low serum vitamin D concentrations and dementia. This evaluation also showed that the quality of the available evidence is not optimal because of both the low methodological quality of the reviews and low quality of the original studies. Interpretation of these systematic reviews should therefore be made with care.

703 visitors, last modified 13 Jul, 2018,
Printer Friendly PDF this page! Follow this page for updates