Dr. Gina's Blog

A new research study published in the Journal Neurology found that people aged between 61 and 87, with higher blood levels of vitamin B12, were six times less likely to experience brain shrinkage (which is associated with dementia) then people with lower levels of B12 in their blood.

Prior studies on the link between B12 and dementia focused on how increased levels of B12 and other B vitamins were linked to low levels of homocysteine, an amino acid that increases risk of dementia and cognitive impairment.

This study, which followed 107 volunteers, found another connection between B12 and the brain- the prevention of brain shrinkage.

The best sources of B12 are meat, fish, milk and eggs. Unfortunately these foods are problematic for people with health challenges as they are foods of animal origin that tend to be more difficult to digest.  Furthermore, such foods are often tainted with pesticides (stored in animal fat), heavy metals, and hormones.

Interestingly enough, people studied in this trial were NOT shown to be deficient in vitamin B12 using standard blood tests.  In my practice, I will test for B12 just to make sure a patient does not show elevated levels, before prescribing subcutaneous vitamin B12 shots, or vitamin B12 supplementation (often in the form of a complete multivitamin formula).  However, a patient certainly does not need to show a B12 deficiency to derive benefit from this vitamin. B12 therapy is effective for weight loss, mental function, energy and depression.

In health,

–Dr. G

Study details

Vogiatzoglou and co-workers recruited the community-dwelling volunteers and collected blood samples to measure levels of vitamin B12, holotranscobalamin (holoTC), methylmalonic acid, total homocysteine, and folate. Brain volume loss per year was calculated using MRI scans.

Over five years of study, the researchers noted a greater decrease in brain volume among people with lower vitamin B12 and holoTC levels.

Indeed, people with lower levels of B12, defined as blood levels below 308 picomoles per litre, were six times more likely to experience brain shrinkage, said the researchers. On the other hand, high levels of methylmalonic acid or homocysteine, or low folate levels were not linked to brain volume loss.

“Low vitamin B12 status should be further investigated as a modifiable cause of brain atrophy and of likely subsequent cognitive impairment in the elderly,” stated the researchers.

It is important to note that none of the volunteers were (known to be) vitamin B12 deficient.

“Previous research on the vitamin has had mixed results and few studies have been done specifically with brain scans in elderly populations. We tested for vitamin B12 levels in a unique, more accurate way by looking at two certain markers for it in the blood,” said Vogiatzoglou.

The potential of supplements

Commenting independently on the results, Dr Susanne Sorensen from the Alzheimer’s Society said: “Shrinkage is usually associated with the development of dementia.

“As vitamin B may be given as a food supplement, it may be useful to include tests of vitamin B levels in the general assessment of health of older individuals.

“This is another example of why it is crucial for people to lead a healthy lifestyle with a balanced diet rich in B vitamins and antioxidants.”

B12 for brain

A University of Oxford study reported in 2007 that increased vitamin B12 levels may reduce the rate of age-related cognitive decline and dementia by 30%.

The study, published in the American Journal of Clinical Nutrition, followed 1648 participants for 10 years and also found that increased levels of the amino acid homocysteine doubled the risk of dementia or cognitive impairment.

Previously, epidemiological studies have reported that high levels of the amino acid homocysteine are associated with suspected or confirmed dementia. Indeed, the Framinghamstudy reported that people with homocysteine levels above 14 micromoles per litre of serum had twice the risk of dementia.

Source: Neurology

9 September 2008, Volume 71, Pages 826-832

“Vitamin B12 status and rate of brain volume loss in community-dwelling elderly”

Authors: A. Vogiatzoglou, H. Refsum, C. Johnston, S. M. Smith, K. M. Bradley, C. de Jager, M. M. Budge, A. D. Smith