Indication: Alzheimer’s disease (AD)


Source: JAMA, October 15, 2008;300(15):1819-21.

Research: Researchers conducted a multi-center, randomized, double-blind, controlled clinical trial of high-dose folate, vitamin B(6) and vitamin B(12) supplementation in 409 (of 601 screened) individuals with mild to moderate AD (Mini-Mental State Examination scores between 14 and 26, inclusive) and normal folic acid, vitamin B(12) and homocysteine levels. The study was conducted between February 20, 2003, and December 15, 2006, at clinical research sites of the Alzheimer Disease Cooperative Study located throughout the U.S. Participants were randomly assigned to 2 groups of unequal size to increase enrollment (60% treated with high-dose supplements [5 mg/d of folate, 25 mg/d of vitamin B(6), 1 mg/d of vitamin B(12)] and 40% treated with identical placebo); duration of treatment was 18 months. Researchers were looking to measure the changes in the cognitive subscale of the Alzheimer Disease Assessment Scale (ADAS-cog).

Results: A total of 340 participants—202 in active treatment group and 138 in placebo group—completed the trial while taking the study medications. Al­though the vitamin supplement regimen was effective in reducing homocysteine levels, it had no beneficial effect on the primary cognitive measure, rate of change in ADAS-cog score during 18 months or on any secondary measures. Further, a higher quantity of adverse events involving depression was observed in the group treated with vitamin supplements. Investigators concluded that this regimen of high-dose B vitamin supplements does not slow cognitive decline in individuals with mild to moderate AD.