September 21st, 2012

Elderly With Low Vitamin B12 Risk Brain Shrinkage And Cognitive Decline

Articles in: Neurology / Neuroscience; Alzheimer's / Dementia
Article Date: 26 Sep 2011

Elderly individuals with low blood vitamin B12 levels have a greater risk of brain shrinkage and losing their cognitive skills, researchers from Rush University Medical Center, Chicago reported in the journal Neurology. Foods rich in vitamin B12 are mainly from animals and include, eggs, milk, liver, meat, and fish.

Christine C. Tangney, Ph.D. and team carried out a study with 121 individuals aged at least 65 years from the south side of Chicago. They underwent blood tests to check for their levels of B12 and B12-related metabolites which can give an indication of a B12 deficiency. They were also assessed for memory and other cognitive skills. About four-and-a-half years later magnetic resonance imaging (MRI) scans of their brains were taken to see how big their brains were, as well as identifying some other signs of brain damage.

Those with four of five markers for vitamin B12 deficiency were found to have a higher risk of getting lower cognitive test scores and smaller total brain volumes.

Christine C. Tangney said:

"Our findings definitely deserve further examination. It's too early to say whether increasing vitamin B12 levels in older people through diet or supplements could prevent these problems, but it is an interesting question to explore. Findings from a British trial with B vitamin supplementation are also supportive of these outcomes."

Cognitive scores ranged from -2.18 to +1.42 - the average score was 0.23. Homocysteine is a marker of B12. For every rise of one micromole per liter of homocysteine cognitive scores dropped by 0.03 points.

It was not the vitamin B12 blood level that was linked to smaller brain size or cognitive problems, Tangney explained. It was the markers that indicate B12 deficiency. Low vitamin B12 is much harder to detect in elderly individuals.

The National Institute of Aging funded the study.

Vitamin B12
Vitamin B12 or Cobalamin is a water soluble vitamin - it dissolves in water and travels through the bloodstream. It is one of eight B vitamins. The human body cannot store Vitamin B12, any excess is excreted through urine.

The molecular formula for vitamin B12 is C63H88CoN14O14P.

Cobalamin is a general term for compounds containing the dimethylbenzimidazolylcobamide nucleus of vitamin B12.

Vitamin B12 plays a key role in normal nervous system functioning and brain development. It is also involved in the formation of red blood cells.

Cobalamin plays a role in the metabolism of every cell in the human body, experts say. It affects DNA synthesis and regulation, as well as the synthesis of fatty acids and energy production.

Structurally, vitamin B12 is the most complicated of all the vitamins, as well as being the largest. Cobalamin can be industrially produced through bacterial fermentation synthesis.

Cobalamin
Vitamin B12 is a large molecule, the most complicated of all the vitamins

Vegans should take vitamin B12 dietary supplements to avoid deficiency, because this vitamin comes from animal sourced proteins. Supplements are generally presented as cyanocobalamin, which the body easily converts to the active forms of methylcobalamin and 5-deoxyadenosylcobalamin.

NOTE: Supplements should not be taken orally but either by Intramusculary injections or Sublingual tablets to dissolve under the tongue. Stomach acids and the lack of stomach enzymes present in younger people prohibit the absorption of an oral dose of B12 in the older patient.