Abstract
Background: The status of vitamin B12 and folate has been implicated in the development and progression of Alzheimer's disease. Methods: The study explored this issue through a retrospective case-control study design, with follow up of the case group for 18 months. The case group (n = 136) comprised patients 65 years or older diagnosed with Alzheimer's disease and having a Mini-mental State Examination score (MMSE) of <= 27. The control group comprised healthy adults 65 years or older (n = 338) with a MMSE score of >27. Results: Vitamin B12 and folate levels were not found to differ between case and control groups. B12 and folate status at baseline was not predictive of disease progression in the case group. Discussion: This lack of association differs from other studies which have shown a protective effect of vitamin B12 and folate on cognitive decline.