High Vitamin D Levels in Brain Tissue May Lead to Better Cognitive Function
Michelle Milliken
Vitamin D is known to benefit bone health, by helping the body absorb and retain phosphorus and calcium. Other research has indicated that it helps control infections and reduce inflammation, as well. A new study finds that it may also be helpful for those living with cognitive decline.
Researchers from Tufts University recently examined the link between vitamin D levels in brain tissue and the brain health of patients living with cognitive decline. According to findings published in Alzheimers & Dementia: The Journal of the Alzheimer's Association, the higher the levels of vitamin D that these patients had in their brains, the better their cognitive function.
Kyla Shea, lead author and associate professor at Tufts' Friedman School of Nutrition Science and Policy, says, "Many studies have implicated dietary or nutritional factors in cognitive performance or function in older adults, including many studies of vitamin D, but all of them are based on either dietary intakes or blood measures of vitamin D. We wanted to know if vitamin D is even present in the brain, and if it is, how those concentrations are linked to cognitive decline."
To determine this, the team examined brain tissue samples from 209 participants in the Rush Memory and Aging Project, an Alzheimer's study that began in 1997. When participants joined the study, they were older adults without any signs of cognitive impairment. Over the following years, their cognitive function was studied, and their brain was analyzed after death.
The Tufts team focused their study on four regions of the brain: two associated with Alzheimer's changes, one associated with types of dementia linked with blood flow, and one without any known links to Alzheimer's or vascular disease. Within each region, they were looking for vitamin D. They discovered that vitamin D was present in the tissue, and that high levels in all four regions were linked with better cognitive function.
Despite the apparent cognitive benefits, though, vitamin D levels didn't appear to impact physical signs of Alzheimer's, like amyloid plaque buildup or evidence of chronic or microscopic strokes. The team says that means it's unclear how the vitamin may impact brain function.
Shea says, "We now know that vitamin D is present in reasonable amounts in human brains, and it seems to be correlated with less decline in cognitive function. But we need to do more research to identify the neuropathology that vitamin D is linked to in the brain before we start designing future interventions."
The team also noted that vitamin D levels differ between racial and ethnic groups, so a broader, more diverse study is needed, as most of the participants in this study were white. They hope that further research may help determine if vitamin D could help ward off dementia.
