Researchers have found that low level of vitamin D could be related to dementia and Alzheimer’s, one of the most common forms of dementia. Direct source of Vitamin D includes the sun and foods like nuts, lentils and fatty fish.

A team of researchers at the University of California at Davis's Alzheimer's Disease Center jointly studied the association between blood levels of vitamin D. They even studied the changes in memory and thinking ability in 382 adults over an average of just under 5 years.

The study participants were from the age group of 76 years. The group in total included nearly 1589 whites, 113 African Americans and 96 Hispanics.

Researchers said less than 18% of the study participants had dementia, 33% had mild cognitive impairment, and 50% were normal.

Study researchers looked at blood vessels of 25-hydroxyvitamin D (25-OHD), a form into which the body converts the vitamin D made by skin when it gets exposed to sunlight and from foods like eggs, oily fish, and dairy foods.

After analyzing the team found that participants with dementia had lower vitamin D levels than those with mild cognitive impairment or whose memory was normal. They noted that over the course of the study individuals with low vitamin D levels had a more rapid decline in cognitive function and in the ability to recall past personal experiences.

As per estimates, almost half of Americans over age 65 have insufficient or deficient levels of vitamin D; Non-whites are more likely to have levels that are too low, the study noted.

Previously conducted studied have linked low vitamin D to a higher risk of dementia and significant problems in memory and managing overall thinking processes.