London, England (CNN) -- Daily doses of vitamin B can halve the rate of brain shrinkage in elderly people with mild cognitive impairment (MCI), which can be a precursor to Alzheimer's, researchers at Oxford University said Thursday. The two-year clinical trial is the largest to study the effect of vitamin B on MCI and one of the first disease-modifying trials in the Alzheimer's field to show positive results, the researchers said. The study followed 168 volunteers with mild memory problems, half of whom took a high-dose vitamin B tablet for two years and the other half who took a placebo.
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Vitamin B could halve the rate of brain shrinkage in those with mild cognitive impairment
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MCI can be a precursor to Alzheimer's and other forms of dementia
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The benefits of certain B vitamins are already known
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Researchers caution that further and larger studies are needed to confirm the results
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