18 Aug 2014 --- A new study has found a strong association between baseline vitamin D concentrations and the risk of incident all-cause dementia and Alzheimer’s disease. The research, published in Neurology , suggests that vitamin D ‘sufficiency’ in the context of dementia risk may be in the region of 50nmol/L. High rates of vitamin D deficiency are found among older adults with more two-thirds of the US population not meeting the estimated average requirement (EAR) of vitamin D .