BDNF and Cognitive impairment: Our study results were partly in agreement with G Hajiluian et al. who reported that Vitamin D significantly increased time spent in MWM probe test, oxidative stress and reversed HFD-induced cognitive impairments via reduction of NF-κB concentrations, BBB permeability and elevation of BDNF (Brain-derived neurotrophic factor) in the hippocampus (Hajiluian et al. 2017).