It seems that Vitamin B supplements don't slow cognitive decline in patients suffering from mild to moderate Alzheimer's disease, according to a new study published in the Oct. 15 issue of The Journal of the American Medical Association.

Researchers who studied the vitamin B said patients with Alzheimer’s, the most common form of dementia, shouldn’t take the nutrient.

The findings suggest that scientists succeeded “in lowering homocysteine levels, but this did not translate into cognitive or clinical benefits," asserted lead researcher Dr. Paul S. Aisen, a professor at the University of California, San Diego, Department of Neurosciences. What was disappointing is that is that high-dose B vitamin treatment proved unsuccessful in people with Alzheimer's, Aisen said.

The study included 202 Alzheimer’s patients who took high-dose B-vitamin supplements (a combination of vitamin B12, vitamin B6 and folic acid) and 138 patients who were given placebo for a year and a half. Using the Alzheimer's Disease Assessment Scale, researchers measured the rate of cognitive decline.

Over the 18 months of follow-up, they were disappointed for not finding any reduction in cognitive decline. However, they discovered that vitamin B supplements diminished homocysteine levels.

“The precise reasons the Alzheimer Disease Cooperative Study failed to detect any beneficial effect of B vitamins on the rate of cognitive decline remain unclear,'' said Robert Clarke and Derrick Bennett, both with the University of Oxford in England.

On top of that, the results of the study also showed that patients taking high-dose vitamin B supplements had a larger number of symptoms of depression than people receiving placebo.