Here’s another reason to check your vitamin D levels. A new study has found that people with higher levels of Vitamin D in midlife have fewer toxic tangles of tau protein in their brain, a factor linked to Alzheimer’s disease.

A team of international researchers found that the more vitamin D in a person’s system in middle age predicted fewer of these tau tangles in later age.

Vitamin D is believed to play a protective role in brain health by helping to regulate processes that may prevent the formation of tau tangles. Tau tangles are abnormal accumulations of protein that disrupt communication between neurons and are a hallmark of Alzheimer’s disease. By maintaining sufficient levels of vitamin D, individuals may reduce their risk of developing these toxic tangles, potentially lowering their chances of cognitive decline as they age.

According to ScienceAlert, this doesn’t prove a cause and effect but the scientists said the connection is worth investigating further.

"These results suggests that higher vitamin D levels in midlife may offer protection against developing these tau deposits in the brain and that low vitamin D levels could potentially be a risk factor that could be modified and treated to reduce the risk of dementia," said neuroscientist Martin David Mulligan, from the University of Galway in Ireland. "Of course, these results need to be further tested with additional studies."

Brain scans from 793 adults who were not diagnosed with Alzheimer’s disease at age 39 and taken again 16 years later measured the levels of tau and amyloid-beta, two proteins associated with Alzheimer’s disease.

The brain needs both of these proteins to stay healthy, but when their behavior becomes irregular, they can damage the neurons in the brain affecting communication. The study didn’t find any association between vitamin D levels and amyloid-beta, but it concluded that the more vitamin D in someone’s system in middle age reduced their risk of developing tau protein tangles later in life.

Previous studies have shown that vitamin D does boost the brain’s immune system and a lack of it has been linked with erratic tau proteins in mice. While there are many factors that contribute to Alzheimer’s disease that affects over 7.2 million Americans, the study published in Neurology Open Access suggested that it’s worth boosting our intake of vitamin D by eating more fish, fortified foods, and enjoying more sunshine.

"These results are promising, as they suggest an association between higher vitamin D levels in early middle-age and lower tau burden on average 16 years later," said Mulligan. "Midlife is a time where risk factor modification can have a greater impact."