University of Manchester scientists, in collaboration with colleagues from other European facilities, compared the cognitive performance of more than 3,000 men ages 40-79 years at eight centers in Europe.
Dr. David Lee of Manchester's School of Translational Medicine found that men with higher levels of vitamin D -- synthesized in the skin following sun exposure but also found in certain foods such as oily fish -- performed consistently better in a simple and sensitive neuropsychological test that assesses an individual's attention and speed of information processing.
"Previous studies exploring the relationship between vitamin D and cognitive performance in adults have produced inconsistent findings but we observed a significant, independent association between a slower information processing speed and lower levels of vitamin D," Lee said in a statement.
"The main strengths of our study are that it is based on a large population sample and took into account potential interfering factors, such as depression, season and levels of physical activity."
The association between increased vitamin D and faster information processing was more significant in men age 60 and older although the biological reasons for this remain unclear, Lee said.
The findings are published in the Journal of Neurology, Neurosurgery and Psychiatry.