therapeutic tool in a number of neurological pathologies. More recently, experimental and pre-clinical data suggest a link between vitamin D status and cognitive function. Human studies strongly support a correlation between low levels of circulating 25-hydroxyvitamin D (25(OH)D) and cognitive impairment or dementia in aging populations transcription regulators - has emerged as a serious candidate in nervous system development and function and a. In parallel, animal studies show that supplementation with vitamin D is protective against biological processes Background: During the last 25 years, vitamin D -being a member of the superfamily of nuclear steroid associated with Alzheimer's disease (AD) and enhances learning and memory performance in various animal models of aging and AD. More recently epidemiological associations have been made between low vitamin D and psychiatric disorders not typically associated with abnormalities in brain development such as depression and Alzheimer's disease Aim of the Study: was to review the recent literature to investigate the correlation between vitamin D status  and neurocognitive function. Methods: We searched the medical literature to retrieve studies for the review to 30 November 2017. electronic search in the scientific database from 1965 to 2017– (Medline, Embase, AMED, Psych INFO, the Cochrane Library websites were searched for English Publications were obtained from both reprint requests and by searching the database. Data extracted included authors, country, year of publication, characteristics of patients, pathophysiology, risk factors, clinical manifestations, different diagnostic approaches and treatment modalities. Conclusion: Accumulating evidence in the current literature indicate that vitamin D deficiency is highly prevalent among patients with cognitive impairment, and that low vitamin D status may negatively impact cognition and that hypovitaminosis D is usually associated with increased risk of developing AD and dementia. Nevertheless, while vitamin D supplementation is safe for those with cognitive impairment, there is no solid proof that they will see significant improvement in their symptoms.