Background: Brain aging is a natural process that affects all populations, leading to declines in both cognitive and biological functions. Consequently, promoting healthy brain aging has become a major public health priority. Vitamin D (Vit.D), a crucial hormone involved in calcium regulation, plays diverse roles across various tissues, including the brain, and has been implicated in mitigating age-related cognitive decline. Aim: To investigate the possible neuroprotective effects of Vitamin D in alleviating cognitive dysfunction in aged rat models. Method: Forty male albino rats were divided into 5 groups consisting of 8 rats in each group; control, D-galactose induced brain aging group, Vit.D 100,1000,10000 IU/kg groups respectively. Upon aging induction with D-galactose, Vitamin D therapy was sustained for eight weeks, and cognitive function was measured through the Novel Object Recognition Test (NORT) and the Barnes test. At the study’s endpoint, biochemical markers were measured; amyloid β (Aβ), MDA and GSH in hippocampal tissue.