In a new study of 3,000 European men aged 40 to 79, those with high levels of vitamin D did better on memory and information processing tests, suggesting the vitamin could protect cells or key signalling pathways in the brain, the BBC reports. The study, which comes from the University of Manchester, follows another published in January that found high levels of the vitamin improves mental agility in the elderly. The latest study, published in the Journal of Neurology Neurosurgery and Psychiatry, showed men with high levels of the vitamin performed best on a range of tests. Those who had low levels (35 nmol/litre or less) performed the worst. Vitamin D, which comes from fish and sun exposure, might trigger an increase in protective hormonal activity in the brain, researchers suggest, or may boost antioxidants to detoxify the brain.