HIGHER levels of vitamin D, synthesised in the skin after being exposed to the sun and found in oily fish, are associated with increased brain power among middle-aged men, according to a British study.

The link between increased vitamin D and faster information processing "was more significant in men aged over 60 years old," read the report, to appear in The Journal Of Neurology, Neurosurgery And Psychiatry on Thursday.

The study, conducted by researchers from the University of Manchester in collaboration with other European specialists, compared the cognitive performance of more than 3000 men between the ages of 40 and 79 years. Men with higher levels of vitamin D "performed consistently better in a simple and sensitive neuropsychological test that assesses an individual's attention and speed of information processing".

Researchers "observed a significant, independent association between a slower information processing speed and lower levels of vitamin D," said the study's lead author, David Lee, at Manchester's school of translational medicine.

The study took into account other possible factors, such as depression, season and levels of physical activity.

The main source of vitamin D is ten to 15 minutes daily exposure to sunlight. Oily fish are also an excellent source of vitamin D. A separate 2008 study by researchers in Amsterdam showed that a lack of vitamin D could increase the risk of psychiatric problems among older people.

Agence France-Presse