A substance called homocysteine is known to be involved in neurological diseases, including Alzheimer's. Vitamin B is known to reduce levels of homocysteine in the body so some scientists wonder whether vitamin B supplements might help to stave off the condition. A study of 340 people by scientists from the Alzheimer's Disease Cooperative Study compared those participants taking a high-dose vitamin B supplement and those taking a placebo. Unfortunately the study found no differences in cognitive performance between the two groups and those taking the vitamin supplement were more likely to show symptoms of depression.
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