Vitamin D, which can be synthesized in our skin in response to sunlight and is also found in small amounts in some foods, has receptor proteins located in neurons and some brain cells. It plays a critical role in protecting the nervous system, supporting critical brain functions, and preventing oxidative brain damage.

However, a surprising half of the population is either deficient or deficient in vitamin D, and rates can vary greatly by race and ethnicity. Vitamin D deficiency is of particular concern because it is associated with cognitive impairment and dementia. In addition, new research is emerging to suggest that adequate levels of vitamin D may prevent problems with glucose regulation, including the onset of diabetes.

A recent review of studies focused on vitamin D insufficiency and cognitive function in adults. The review included nine studies involving 69,643 participants with a mean age of 53.6 years. People with vitamin D deficiency or insufficiency were found to have reduced executive function, processing speed, and visual perceptual abilities. Moreover, five studies linked vitamin D deficiency to an increased risk of dementia.

Two studies found that the severity of memory and cognitive impairment was directly proportional to the degree of vitamin D deficiency.

One study found that vitamin D supplements may improve cognitive and memory functions, indicating the vitamin’s potential to fight cognitive decline.

However, it is important to note that the study had some limitations, including the underrepresentation of certain populations, such as people of African, Asian, and Latin American descent. The authors also noted that large-scale randomized controlled trials will be needed to examine the full range of effects of vitamin D deficiency and supplementation and their relationship to cognitive health in the aging brain.

Another new study1 studied the effects of vitamin D on glucose regulation and diabetes risk. Adequate levels of vitamin D were found to reduce the risk of developing the disease in participants.