Evaluation the relationship between serum level of vitamin D and cognitive impairment in elderly patients

Background: Vitamin D deficiency is a common disorder in elderly, previously suggested to be associated with cognitive impairment. This study was aimed to determine the association between 25(OH) vitamin D and cognitive impairment in the elderly. Methods: In this case-control study, 35 individuals who met criteria of cognitive impairment were examined against 35 individuals who did not have cognitive impairment. Serum 25(OH) vitamin D levels were measured in both fasting groups by ELISA kits. Data were collected using a checklist containing demographic data and serum vitamin D levels in two groups and analyzed using SPSS 16 software. Results: The mean age of the control group was 67.91±4.78 years and of the case group was 68.91±3.63 years (p=0.328). The mean serum level of 25(OH) vitamin D in the control and case groups was 37.28 ng/ml and 23.06 ng/ml, respectively. The observed difference was statistically significant (p=0.003). 20 (57.1%) of control group and 10 (28.6%) of case group had sufficientlevels of vitamin D (p=0.01). The odds ratio of cognitive impairment in the case group was 3.3 times higher than control group, which was also statistically significant (p=0.001). Conclusion: Elderly people with cognitive impairment have lower levels of vitamin D than healthy ones with same age, which may be related to their cognitive impairment. However, confirmation of the results of this study requires further studies with a larger sample sizes.