Effects of vitamin B12 on cognitive function in elderly patients

Abstract

AbstractBackgroundEstablishing preventive and therapeutic methods for Alzheimer's disease (AD) is an urgent issue. Because Vitamin B12(VB12) has a neuroprotective effect on the central nervous system, it has begun to receive attention. Recently, we found that VB12 can suppress β‐amyloid toxicity in vitro. Besides, it has been reported that VB12 might be useful for keeping memory in Mild Cognitive Impairment (MCI). To clarify the effects of VB12 in AD and MCI patients, we examined the effects of the VB12 on cognitive function and regional cerebral blood flow (rCBF).MethodWe examined 46 participants who consulted to our memory clinic. They were divided into three groups: Alzheimer's disease (AD), mild cognitive impairment (MCI), and healthy controls (HC) based on the National Institute on Aging‐Alzheimer’s Association (NIA‐AA) diagnostic criteria. We used Wechsler Memory Scale‐Revised(WMS‐R) to assess the cognitive function and evaluate what kind of function is degraded. Three‐dimensional stereotactic surface projection(3D‐SSP)was used to quantify the rCBF of hippocampus, thalamus, and callosomarginal regions, which had a well‐established connection with AD. Multiple regression analysis was conducted to examine the correlations among serum VB12, WMS‐R, and rCBF in each group.ResultRegarding the correlations between VB12 and memory function, we found that the VB12 was significantly correlated with the WMS‐R scores of visual paired association I/II in the MCI group and the verbal paired associates I in the AD group (all, p<0.05). Besides, there were significant correlations between VB12 and WMS‐R scores of the visual reproduction I, logical memory I, and visual memory span in the HC group (all, p<0.05). Regarding the correlations between VB12 and rCBF, VB12 concentration was significantly correlated with the rCBF of the left hippocampal in the MCI group (all, p<0.05). Neither AD nor HC groups showed significant correlations between rCBF and VB12. Finally, the rCBF of the left hippocampus was positively correlated with visual paired association I/II(all, p<0.05).ConclusionThese results suggested that VB12 affects memory function and rCBF, especially in the MCI. Considering the relationship between WMS‐R and rCBF, VB12 may affect the progression of dementia. The early intervention with VB12 can be more effective in AD treatment strategies.