An important link that scientists have worked to establish, exists between vitamin D and cognitive function.
The study was led by epidemiologist Katherine Tucker with the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts University in Boston, Mass.
Metabolic pathways for vitamin D have been found in the hippocampus and cerebellum areas of the brain involved in planning, processing, and forming new memories. This suggests that vitamin D may be implicated in cognitive processes.
The study involved more than 1,000 participants receiving home care. The researchers evaluated associations between measured vitamin D blood concentrations and neuropsychological tests.
Elders requiring home care have a higher risk of not getting enough vitamin D because of limited sunlight exposure and other factors.
The participants, ages 65 to 99 years, were grouped by their vitamin D status, which was categorized as deficient, insufficient, or sufficient. Only 35 percent had sufficient vitamin D blood levels.
They had better cognitive performance on the tests than those in the deficient and insufficient categories, particularly on measures of "executive performance," such as cognitive flexibility, perceptual complexity, and reasoning.
The associations persisted after taking into consideration other variables that could also affect cognitive performance.
The 2009 study appears in the Journals of Gerontology, Series A, Biological Sciences and Medical Sciences.