Dementia associated with low vitamin D in two thirds of studies – systematic review May 2013

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. m.h.emmelotvonk at umcutrecht.nl
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

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See also VitaminDWiki

• Alzheimer’s and Parkinson’s diseases associated with low vitamin D – meta-analysis June 2013
• "Senior moment" 25X more likely with low vitamin D - Feb 2012
• All items in category Cognition and vitamin D 389 items
• Overview Alzheimer's-Cognition and Vitamin D which had the following summary July 2013

- FACT: Cognitive decline is associated with low vitamin D levels. 19X more likely if < 10 ng of vitamin D
- FACT: Dementia is associated with low vitamin D levels.
- FACT: Alzheimer's Disease is associated with low vitamin D levels. 4X less likely if less likely if high vitamin D
- FACT: Every single risk factor listed for Alzheimer's Disease is also a risk factor for low vitamin D levels
- FACT: Elderly have very low levels of vitamin D (at least 4 reasons)
- FACT: Elderly cognition gets worse as the elderly vitamin D levels get even lower (while in senior homes)
- OBSERVATION: Elderly who get more vitamin D increase their vitamin D levels
- OBSERVATION: Reports of increased vitamin D levels result in improved cognition
- OBSERVATION: Alzheimer's Disease has been seen to halt when vitamin D was added.
- OBSERVATION: Several vitamin D INTERVENTION clinical trials are underway to prove the above - 12 as of June 2013
- OBSERVATION: Several studies have shown a strong association of Alzheimer's Disease with a gene mutation which reduces vitamin D effectiveness
- OBSERVATION: 2 Meta-analysis in 2012 agree that Alzheimer's Disease. associated with low vitamin D
- FACT: Vitamin D is very low cost and has very very few side effects
- CONCLUSION: Everyone concerned about cognitive decline or Alzheimer's Disease should start taking vitamin D