Vitamin D may cut the risk of dementia by up to one third, according to new research. A team at Tufts University in the US looked at levels of the vitamin in nearly 300 adults participating in a long term study of Alezheimer’s that began in 1997. They investigated four regions of the braiin, two of which wedre linked with the disease, one of which was known to be involved in dementia and a fourth which was not thought to have any connection with age related cognitive decline. The vitamin was present in all four – and the more there was, the better the cognitive function. Though they stress more research is needed to establish why, they found that higher concentrations were associated with a 25% – 33% lower risk of dementia or mild cognitive impairment among those participants visiting them for the last time before dying.