Dementia associated with low vitamin D in two thirds of studies – systematic review

The association between vitamin D and cognition: a systematic review.

Ageing Res Rev. 2013 May 29. pii: S1568-1637(13)00026-3. doi: 10.1016/j.arr.2013.05.004. van der Schaft J, Koek HL, Dijkstra E, Verhaar HJ, van der Schouw YT, Emmelot-Vonk MH. [email protected]

Department of Geriatrics, University Medical Center Utrecht.

Highlights

  • We conducted a systematic literature review in Pubmed and Embase.

  • We examine the association between levels of vitamin D and cognition.

  • Lower vitamin D levels are associated with worse cognitive function tests.

  • Lower vitamin D levels are associated with a higher frequency of dementia.

Vitamin D insufficiency and deficiency are a major health care problem. The association between vitamin D levels and cognitive function is still under debate. We conducted a systematic review to assess the association between levels of vitamin D and cognition. Therefore, the databases of Embase and Pubmed were searched through June 2012 for observational studies relating vitamin D levels to cognition. Our initial search yielded 2182 articles. After applying exclusion criteria, there were 28 studies eligible for inclusion: 25 cross-sectional and 6 prospective studies (3 studies show cross-sectional as well as prospective data).

The main finding of the 25 cross-sectional studies was a statistically significant worse outcome on one or more cognitive function tests or a higher frequency of dementia with lower vitamin D levels or intake in 18 out of 25 (72%) studies, whereas 7 (28%) studies failed to show an association.

Four out of 6 (66.7%) prospective studies showed a higher risk of cognitive decline after a follow-up period of 4 to 7 years in participants with lower vitamin D levels at baseline. In conclusion, this review supports the hypothesis that hypovitaminosis D is associated with worse outcome on one or more cognitive function tests or a higher frequency of dementia in cross-sectional as well as prospective studies. Further studies should focus on the role of vitamin D supplementation in the prevention of cognitive decline in participants with low vitamin D levels.

Copyright © 2013. Published by Elsevier B.V. PMID: 23727408


See also Vitamin D Life

Tags: Cognitive