Vitamin D and progression in Mild Cognitive Impairment (MCI)

Abstract

Background and objective: Data from cross-sectional and longitudinal studies suggest an association between cognitive impairment and vitamin D (VD) deficiency. However, the association of VD status with MCI conversion to dementia has not been fully explored.The aim of this study was to investigate the association between serum 25-hydroxyvitamin D [25(OH)D] status and progression of MCI to dementia in older adults.Patients and methods: We evaluated patients with diagnosis of MCI according to Mayo Clinic criteria (Petersen, 2001), who were followed for at least 5 years and healthy controls (HC). MCI patients were classified as amnesic or non-amnesic according to presence of memory deficit at baseline. Levels of VD were recorded. VD deficiency was defined as 25(OH)D < 20 ng/ml, insufficiency as 20 to 30 ng/ml, normal > 30 ng/ml. We compared VD levels of patients converted to dementia with those who remain stable. Both groups were compared with HC.Results: 216 subjects were included, 103 MCI and 113 HC. Mean age were 74,16 ± 6,7, 84,1% were females, without demographic differences between groups. The values of VD were similar in both groups. We found that MCI patients with VD deficiency had higher rates of conversion to dementia than the other groups (p = 0,003). Amnesic MCI patients converted to Alzheimer and non amnesic to non-Alzheimer dementias (p < 0,0001).Conclusion: Our findings suggest a significant association of lower VD levels with progression to dementia in MCI patients. A long-time major placebo-controlled randomized trial of vitamin D supplementation in patients with MCI should be started. Background and objective: Data from cross-sectional and longitudinal studies suggest an association between cognitive impairment and vitamin D (VD) deficiency. However, the association of VD status with MCI conversion to dementia has not been fully explored. The aim of this study was to investigate the association between serum 25-hydroxyvitamin D [25(OH)D] status and progression of MCI to dementia in older adults. Patients and methods: We evaluated patients with diagnosis of MCI according to Mayo Clinic criteria (Petersen, 2001), who were followed for at least 5 years and healthy controls (HC). MCI patients were classified as amnesic or non-amnesic according to presence of memory deficit at baseline. Levels of VD were recorded. VD deficiency was defined as 25(OH)D < 20 ng/ml, insufficiency as 20 to 30 ng/ml, normal > 30 ng/ml. We compared VD levels of patients converted to dementia with those who remain stable. Both groups were compared with HC. Results: 216 subjects were included, 103 MCI and 113 HC. Mean age were 74,16 ± 6,7, 84,1% were females, without demographic differences between groups. The values of VD were similar in both groups. We found that MCI patients with VD deficiency had higher rates of conversion to dementia than the other groups (p = 0,003). Amnesic MCI patients converted to Alzheimer and non amnesic to non-Alzheimer dementias (p < 0,0001). Conclusion: Our findings suggest a significant association of lower VD levels with progression to dementia in MCI patients. A long-time major placebo-controlled randomized trial of vitamin D supplementation in patients with MCI should be started.