Senior citizens may have greater difficulty than younger people maintaining adequate levels of vitamin B12. But those who have higher levels of vitamin B12 in their bloodstreams have a lower likelihood of developing Alzheimer’s disease. The research was done in more than 250 Finnish people. At the start of the study none of them had dementia, and all gave blood samples. Seven years later, about 6 percent of the participants were diagnosed with Alzheimer’s disease. Those with lower levels of B12 were more likely to have developed dementia.
[Neurology, Oct. 19, 2010]