These findings were further supported by studies reporting that 1α,25-dihydroxy-vitamin D3 significantly decreased the concentrations of Aβ in the cerebral cortex of mouse AD model (Durk et al., 2014) and increased ABCB1 activity and expression in brain capillaries of rats and mice, as well as in isolated endothelial cells of human micro-vessels (Chow et al., 2011; Durk et al., 2012). This evidence concerns the gene ABCB1 and Alzheimer disease.