New research by the University of Galway in Ireland has found that the vitamin D in midlife can prevent the buildup of toxic tangles of tau protein in the brains of those with Alzheimer's disease. The study, which compared blood samples and brain scans from 793 adults, found that while the link was not directly proven, it suggests an association worth looking at. The researchers suggest that higher vitamin D levels in midlifends may offer protection against developing these deposits and could potentially be a risk factor that could be modified and treated to reduce the risk of dementia. However, further testing of these findings will require.