Vitamin B12 And Alzheimer's

While your body only requires small amounts of vitamin B-12 to avoid deficiency, it needs it for some pretty important purposes, including promoting key aspects of brain health. Deficiency of this vitamin has been linked to an increased risk of developing Alzheimer's disease, which is characterized by significant cognitive impairment that can affect your memory and personality as well as cause confusion. While getting enough B-12 is likely not a magic bullet for preventing this incurable disease, research indicates having sufficient levels may lower the risk of developing it.

Connection Between B-12 Levels and Homocysteine Levels

Researchers at the Karolinska Institute in Stockholm, Sweden conducted a seven-year study where they took blood samples of over 270 Finnish participants -- none of which had any form of dementia when the study started. By the study's end, 17 had developed this disease. Their results, which were published in an October 2010 issue of "Neurology," found a correlation between low levels of B-12 and an increased risk of Alzheimer's. Vitamin B-12 helps keep levels of the amino acid homocysteine low -- excess amounts of which might increase damage to the brain. As such, low levels of B-12 will contribute to higher levels. The Swedish researchers found that the higher the homocysteine levels, the more likely the person was to develop this disease while the higher the concentration of active B-12, the less likely the person was to develop Alzheimer's disease. These results were consistent regardless of the presence of individual factors such as smoking habits, blood pressure, body mass index, age and gender. More research is needed to conclude that using B-12 will prevent the development of this disease.

B-12 and Brain Shrinkage

A study conducted at Oxford University and published in a September 2010 issue of the journal "PLos One," studied the effects of supplementation with B-12, folic acid and vitamin B-6 on patients with mild cognitive impairment, a condition that represents a major risk factor for developing Alzheimer's disease, as 50 percent of sufferers go on to develop it. The study specifically looked to see if supplementation slowed the rate of brain atrophy or brain shrinkage. Those taking the high doses of the B vitamins experienced less brain shrinkage and scored higher on cognitive tests. Participants took .8 mg of folic acid, .5 mg of B-12 and 20 mg of B-6 daily. You should not take high doses of any vitamin without talking to your doctor first.

Using B-12 to Treat Alzheimer's Disease

While adequate levels of B-12 appear to decrease your risk of developing Alzheimer's disease, whether or not it can serve as a treatment for it has not been clearly established. Neuropsychologist Glenn Smith, Ph.D, writing for Mayoclinic.com, states that based on available evidence, using B-12 to improve the memory of Alzheimer's patients does not appear to offer benefit in the absence of a deficiency of the vitamin. However, the Oxford study theorizes that the use of B-12 can slow brain shrinkage, which could impact the current course of the disease, not only its development. But whether it would actually produce any benefit once you have contracted the disease has not been established.

Vitamin B-12 Deficiency in Older Individuals

Several groups of people have a greater risk of B-12 deficiency, including older individuals. Your body uses hydrochloric acid, produced in the stomach, to absorb the B-12 naturally found in foods like meat and other animal products. Up to 30 percent of older individuals might not absorb it properly due to insufficient levels of this stomach acid, according to the University of Maryland Medical Center. Therefore, anyone over 50 should take supplements or consume foods fortified with B-12 such as cereals and other grain products. Certain medications that older individuals are more likely to need, can also lower B-12 levels in the body including those that reduce stomach acid like proton-pump inhibitors and H2 blockers, bile acid sequestrants to treat cholesterol, the diabetes medication metformin, and colchicine, used to treat gout.

Supplementation Considerations

Taking larger amounts of any one B vitamin for prolonged periods could lead to an imbalance in levels of the others. For this reason, you might consider taking a B complex supplement that provides all the B vitamins in the proper proportions in addition to your B-12 supplement. Talk to your doctor about a suggested B-12 dosage.