Vitamin D deficiency as a risk factor for dementia: a systematic review and meta-analysis.
BMC Geriatr. 2017 Jan 13;17(1):16. doi: 10.1186/s12877-016-0405-0.
This is a meta-analysis of observational studies
Test vitamin D then wait 5-30 years and see who gets dementia
They did not look at vitamin D levels at time of dementia
Vitamin D levels will drop over the decades due to Diabetes, Multiple Sclerosis, Stroke, etc
Dementia risk factor 1.54 times higher if < 10 ng vs > 20 ng
Important confounders ignored included genes (Alzheimer’s, VDR, etc.), obesity, skin color, etc
See also VitaminDWiki
- Cognition and vitamin D – summary of expert opinions – July 2014
- Vitamin D reduces Alzheimer’s disease in at least 11 ways – Jan 2013
- Cognitive Impairment 1.8 times more likely if low Omega-3– Oct 2016
- Schizophrenia relapses reduced 3X by Omega-3 – RCT Mar 2015
- Cognitive decline in elderly slowed by Omega-3 – meta-analysis May 2015
- Reversal of cognitive decline with multitherapy (not monotherapy) – Sept 2014
- Blacks with strokes having low Vitamin D were 3 times more likely to have cognitive impairment – Nov 2016
- New cognitive problems 3 times more likely in Chinese elderly having low vitamin D – July 2016
- Dementia 13X more likely in elderly with low vitamin D – May 2014
- "Senior moment" 25X more likely with low vitamin D - Feb 2012
- Dementia 19X more likely if low vitamin D – Jan 2012
Items in categories Cognition and Meta-analysis
- Alzheimer’s 1.6X more likely if vitamin D is less than 25 ng – meta-analysis July 2023
- Alzheimer’s patients have less Magnesium – meta-analysis Jan 2022
- Delirium or cognitive problems after surgery 1.5X more likely if low vitamin D –meta-analysis Aug 2022
- 2X higher risk of Alzheimer’s if poor Vitamin D Receptor – Meta-analysis June 2021
- Alzheimer’s Disease risk is 1.9 X higher if Vitamin D deficient- meta-analysis Feb 2020
- Alzheimer’s Disease risk is 1.3X higher if Vitamin D deficient – meta-analysis Nov 2019
- Mental disorders fought by Omega-3 etc. - meta-meta-analysis Oct 2019
- Alzheimer's risk increased 7 percent for every 4 ng decrease in Vitamin D– meta-analysis Nov 2018
- Dementia is associated with low vitamin D - many studies
- Risk of Dementia and Alzheimer's reduced by higher levels of Vitamin D – meta-analysis Feb 2018
- Poor cognition 26 percent more likely if low Vitamin D (29 studies) – meta-analysis July 2017
- Dementia risk factor is increased by 1.5 if low vitamin D – meta-analysis Jan 2017
- Omega-3 helps childhood cognition – meta-analysis April 2016
- Poor cognition associated with low vitamin D in elderly (Asians now too) – meta-analysis March 2016
- Cognitive decline in elderly slowed by Omega-3 – meta-analysis May 2015
- Alzheimer’s disease 21 percent more likely if low vitamin D – meta-analysis Aug 2015
- Parkinson's and Alzheimer's: associations with vitamin D receptor genes and race – meta-analysis July 2014
- Brain (Alzheimer’s) worked better with Vitamin D intervention – meta-analysis July 2013
- Alzheimer’s and Parkinson’s diseases associated with low vitamin D – meta-analysis June 2013
- Alzheimer's Disease more likely with low vitamin D – meta-analysis Oct 2012
- Alzheimer disease associated with 2.5 ng less vitamin D – meta-analysis Sept 2012
- Cognitive Impairment 2.4X more likely if low vitamin D – meta-analysis July 2012
Download the PDF from VitaminDWiki
Sommer I1, Griebler U2,3, Kien C2,3, Auer S4,5, Klerings I2,3, Hammer R6, Holzer P6, Gartlehner G2,3,7.
1Department for Evidence-based Medicine and Clinical Epidemiology, Danube University Krems, Dr.-Karl-Dorrek-Straße 30, 3500, Krems, Austria. isolde.sommer at donau-uni.ac.at.
2Department for Evidence-based Medicine and Clinical Epidemiology, Danube University Krems, Dr.-Karl-Dorrek-Straße 30, 3500, Krems, Austria.
3Cochrane Austria, Danube University Krems, Krems, Austria.
4Department for Clinical Neurosciences and Preventive Medicine, Danube University, Krems, Austria.
5MAS Alzheimerhilfe, Bad Ischl, Austria.
6Institute of Building Research & Innovation ZT-GmbH, Vienna, Austria.
7RTI-UNC Evidence-based Practice Center, Research Triangle Institute International, North Carolina, USA.
BACKGROUND:
Sunlight exposure and high vitamin D status have been hypothesised to reduce the risk of developing dementia. The objective of our research was to determine whether lack of sunlight and hypovitaminosis D over time are associated with dementia.
METHODS:
We systematically searched MEDLINE (via PubMed), Cochrane Library, EMBASE, SCOPUS, Web of Science, ICONDA, and reference lists of pertinent review articles from 1990 to October 2015. We conducted random effects meta-analyses of published and unpublished data to evaluate the influence of sunlight exposure or vitamin D as a surrogate marker on dementia risk.
RESULTS:
We could not identify a single study investigating the association between sunlight exposure and dementia risk. Six cohort studies provided data on the effect of serum vitamin D concentration on dementia risk. A meta-analysis of five studies showed a higher risk for persons with serious vitamin D deficiency (<25 nmol/L or 7-28 nmol/L) compared to persons with sufficient vitamin D supply (=50 nmol/L or 54-159 nmol/L) (point estimate 1.54; 95% CI 1.19-1.99, I2 = 20%). The strength of evidence that serious vitamin D deficiency increases the risk of developing dementia, however, is very low due to the observational nature of included studies and their lack of adjustment for residual or important confounders (e.g. ApoE e4 genotype), as well as the indirect relationship between Vitamin D concentrations as a surrogate for sunlight exposure and dementia risk.
CONCLUSIONS:
The results of this systematic review show that low vitamin D levels might contribute to the development of dementia. Further research examining the direct and indirect relationship between sunlight exposure and dementia risk is needed. Such research should involve large-scale cohort studies with homogeneous and repeated assessment of vitamin D concentrations or sunlight exposure and dementia outcomes.
PMID: 28086755 DOI: 10.1186/s12877-016-0405-0