B vitamins that influence metabolism of the enzyme homocysteine have been considered as a therapeutic option to reduce risk of Alzheimer’s or slow its progression.
But a clinical trial of 409 individuals with mild to moderate Alzheimer’s disease showed that even though vitamin B supplements reduced homocysteine levels, it had no beneficial effect on cognitive abilities.
Authors found that depression symptoms were more common in the 202 people in the high dose supplement group.
‘Our study does not support the treatment of individuals with mild to moderate AD and normal vitamin levels with B vitamin supplements,” the authors wrote.
Journal of the American Medical Association (2008) 300:1774-1783