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

Yet, an astonishing half of the population is affected by either vitamin D deficiency or insufficiency, and rates can vary widely based on race and ethnic origin. Vitamin D deficiency is particularly concerning, as it has been associated with cognitive impairment and dementia. Plus, there’s emerging research to suggest adequate vitamin D levels may ward off glucose regulation concerns, 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 an average age of 53.6 years. It found that individuals with vitamin D deficiency or insufficiency had reduced executive function, processing speed, and visuoperceptual ability. What’s more, five of the studies linked vitamin D deficiency to an increased risk of dementia.

In two of the studies, the severity of memory and cognitive impairment was found to be directly proportional to the degree of vitamin D insufficiency.

One study found that vitamin D supplementation can increase cognitive and memory function, pointing to the potential of this vitamin to combat cognitive decline.

However, it’s important to note the research had some limitations, including the underrepresentation of certain populations, such as people from Africa, Asia, and of Hispanic heritage. The authors also noted that larger randomized controlled trials will be needed to explore the full range of effects of vitamin D deficiency and supplementation, as well as their connection to cognitive health in the aging brain.

Another new study1 looked into the effects of vitamin D on glucose regulation and diabetes risk. It found that adequate vitamin D levels lowered participants’ risk of developing the condition.