http://archinte.ama-assn.org/cgi/content/abstract/170/13/1135
Cognitive decline is a really horrible subject to think about, but looking at this study gives hope that simple solutions are out there for those who are suffering from non-neurodegenerative disease linked cognitive decline.
A 6-year study done at University of Exeter has shown that people over 55 with low vitamin D levels are 60% more likely to suffer from substantial cognitive decline than those with adequate levels of the nutrients.