A lack of vitamin D has already been linked in several studies to depression. Now it appears a deficiency of this crucial nutrient could also play a role in robbing the brain of the ability to process information correctly and clearly.
Defined as a person’s ability to process thoughts, cognitive function includes memory and the ability to learn new information, as well as speaking and reading comprehension. Aging is known to affect cognitive function in many people, resulting in memory loss and difficulty thinking of the right words while speaking or writing. But what if a lack of vitamin D could be the culprit that is causing or contributing to cognitive impairment in many elders — and not simply aging by itself? If that’s the case, it offers hope that adequate vitamin D could help keep minds agile and memory sharp.
Research headed by epidemiologist Katherine Tucker with the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts University in Boston, Massachusetts, and published in Journals of Gerontology raises that possibility. 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. So it appears a lack of vitamin D could disrupt these cognitive processes.
Dr. Tucker and her colleagues studied more than 1,000 elders receiving home care. The research team investigated associations between measured levels of vitamin D in the blood of these people, who were all between the ages of 65 and 99, and compared them to results of neuropsychological tests. The participants were then grouped by their vitamin D status, which was categorized as deficient, insufficient, or sufficient.
The researchers noted in a statement to the media that older people needing home care have an elevated risk of not getting enough vitamin D because of their exposure to sunlight is often limited. And, in fact, only 35 percent of the research subjects had sufficient vitamin D levels in their blood for health. Those elders who did have adequate vitamin D scored far better on cognitive tests than those in the deficient and insufficient vitamin D categories, particularly on measures of executive performance, which included cognitive flexibility, perceptual complexity, and reasoning. The associations persisted after taking into consideration other variables that could also have influenced performance on the cognitive ability tests.
Another new study just presented at the Endocrine Society’s 92nd Annual Meeting held in San Diego provides more disturbing evidence that older adults commonly have low vitamin D levels. Researchers from the VU University Medical Center in Amsterdam investigated approximately 1,300 Dutch men and women age 65 and older and found almost 50 percent were deficit in vitamin D.