Can Vitamin B12 Stave Off Alzheimer’s?

By Dr. Randi Fredricks, Ph.D.

Alzheimer's disease (AD) is a neurodegenerative disorder that causes both the loss of memory and the progressive decline of cognitive abilities. The slowly progressive destruction of nerve cells in the brain leads to Alzheimers disease. While it is natural to lose a certain number of nerve cells as we get older, the loss occurs much more rapidly in people suffering from Alzheimer's. As a result, the brain of the victim cannot function normally. In most cases, the exact cause cannot be explained. And while we don’t always know what causes it, we are very familiar with its devastating effects.

Recommended Dietary Allowances (RDA) of nutrients as set by the government been notoriously low. Many nutrition experts believe current RDAs are too low and have asked for major revisions. A study in 2005 determined that many older adults need up 200 times the RDA of vitamin B12 to normalize mild vitamin deficiency.

Individuals with AD often have low blood levels of vitamin B12. One study found lower vitamin B12 levels in the cerebrospinal fluid of patients with AD than in patients with other types of dementia, though blood levels of vitamin B12 did not differ. Vitamin B12 deficiency, like folic acid deficiency, leads to decreased synthesis of methionine and S-adenosyl methionine, adversely affecting methylation reactions. Methylation reactions are essential for the metabolism of components of the myelin sheath of nerve cells as well as neurotransmitters. Also, moderately increased homocysteine levels as well as decreased folic acid and vitamin B12 levels have been associated with AD and vascular dementia.

A study of 164 patients with AD included 76 cases in which the diagnosis was reconfirmed by examination of brain cells postmortum. Compared to 108 control subjects without dementia, the subjects with AD had significantly higher blood homocysteine levels and lower blood levels of both folic acid and vitamin B12.

Researchers at Boston University School of Medicine sampled 1,092 men and women without dementia and followed them for ten years to examine risk factors for dementia. Those with higher plasma homocysteine levels at baseline had a significantly higher risk of developing AD and other types of dementia.

An Italian study of 816 elderly men and women reported that those with elevated homocysteine levels had a significantly higher risk of developing AD or dementia.

Based on these findings, scientists have concluded that plasma homocysteine levels greater than 14 micromol per liter doubles the risk of AD. An increased plasma homocysteine level is clearly a strong, independent risk factor for the development of dementia and AD.

References
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About the Author

Dr. Randi Fredricks, Ph.D. of San Jose Counseling and Psychotherapy is a psychotherapist and author specializing in the treatment of mental health using integrative medicine and natural therapies. She works with individuals, couples, and families at her office in San Jose, California. Dr. Fredricks' publications include the landmark book Healing & Wholeness: Complementary and Alternative Therapies for Mental Health. No part of this article may be reproduced in any form or by any electronic or mechanical means, including information storage and retrieval systems. Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of Dr. Randi Fredricks as articles often present the published results of the research of other professionals. Copyright © 2012. To cite this article, please use the following citation: Fredricks, R. (2008). Healing & Wholeness: Complementary and Alternative Therapies for Mental Health. Bloomington, IN: Author House.