Evidences reveal that vitamin D deficiency and vitamin D receptor genepolymorphism can influence the cognitive abilities of the normal aged subjects.Aim: studying the relationship between the serum level of vitamin D, vitamin Dreceptor gene polymorphism (VDR– Apal & VDR- Taql) and cognitive impairment inelderly.Subjects and methods: The study was conducted on 50 subjects ≥ 60 years old,having ≥ 28 on Mini-mental state examination and <10 on Hamilton Rating Scale ofDepression. Selected subjects were submitted to a battery of psychometric tests thatexamine different cognitive domains, measurement of total serum Ca, TSH, PTH, 25hydroxy vitamin D and genotyping using PCR to detect the polymorphisms of VDRApaIand VDR-TaqI.Results: Vitamin D deficiency was found to be associated with poor performance intests assessing memory and attention, but no relation was found between vitamin Dand performance in tests assessing executive functions, language or visuospatialabilities. VDR-ApaI polymorphism was found to affect the performance in testsassessing memory and psychomotor speed but no effect for VDR-ApaI polymorphismon the performance in tests assessing attention, executive functions, language orvisuospatial abilities. No effect for VDR-TaqI polymorphism on the performance intests assessing attention, memory, executive functions, psychomotor speed, languageor visuospatial abilities. No relation could be established between total serum calciumand the performance in tests assessing attention, memory, executive functions,psychomotor speed, language or visuospatial abilities. Increased plasma level of PTHwas found to be associated with poor performance in tests assessing memory andpsychomotor speed but no relation was found between PTH and the performance intests assessing attention, language, executive functions or visuospatial abilities.Conclusion: Vitamin D deficiency and vitamin D receptor gene polymorphism playan important role in exacerbating cognitive impairment of normal aging.