The body needs vitamin D, along with calcium, to build bones and keep them healthy. If the body does not have enough vitamin D, it cannot effectively absorb calcium. Vitamin D is not reserved for the formation of healthy bones; rather, it is involved with immune and muscle function and it helps keep brain cells healthy. 

That brings us to new research, which found that people with higher vitamin D levels in middle age may have a lower risk of developing dementia. For the study, researchers measured vitamin D blood levels in about 800 adults with an average age of 39 at the beginning of the study. Nearly 16 years later when they were in their 50s, participants had PET scans of their brains to measure the accumulation of tau and beta-amyloid proteins, both of which are tied to increased dementia risk. 

Researchers found that adults with higher vitamin D levels at the beginning of the study had lower levels of tau protein on brain scans taken at middle age. Vitamin D may play an integral role in preventing or slowing down changes in diseases like Alzheimer’s or dementia. It may also have anti-inflammatory effects in the brain, enhancing antioxidant activity and reducing the  amount of abnormal tau protein. 

Higher Vitamin D Levels Associated With Less Tau Buildup

The participants in the study had an average vitamin D blood level of 38 nanogram per milliliter (ng/ml). Measurements below 30 ng/ml were considered low, and nearly one-third of participants fell into this group. Those with high vitamin D levels had less tau buildup in their 50s, including areas of the brain where that protein tends to accumulate first in people who develop dementia. 

Researchers noted that the connection between high vitamin D levels and reduced tau buildup remained steadfast throughout the study. That was even when researchers accounted for several factors that could impact that association, including sex, age, and the exact amount of time from the start of the study to the end. However, the study did not find a link between midlife vitamin D levels and later amyloid buildup. Researchers stated that that is possible because tau buildup begins earlier in the progression of dementia, whereas amyloid tends to build up later in life. 

The Study Had Some Limitations

It’s important to note that the study was not a controlled experiment designed to prove whether or how specific vitamin D levels could directly prevent or slow the progression of dementia. For example, one of the study’s limitations was that the participants were predominantly white. That means the results the researchers found may not apply to people from other racial or ethnic groups. 

Another drawback is that researchers observed vitamin D levels at a single point in time. That makes it near impossible to determine how any changes in vitamin D levels over the years could impact future dementia risk. Even still, the study suggests that vitamin D levels may be a potential risk factor for dementia that people can control. 

What the study results suggest is that low levels of vitamin D in midlife may be a modifiable target to reduce dementia later in life. The results do not prove that vitamin D causes or prevents dementia, though. More studies will be necessary before vitamin D checks are recommended in the community.

Vincent Stevens

Vincent Stevens is the senior content writer at Dherbs. As a fitness and health and wellness enthusiast, he enjoys covering a variety of topics, including the latest health, fitness, beauty, and lifestyle trends. His goal is to inform people of different ways they can improve their overall health, which aligns with Dherbs’ core values. He received his bachelor’s degree in creative writing from the University of Redlands, graduating summa cum laude. He lives in Los Angeles, CA.