Marc Joseph Nutrition - Blog

Vitamin B12 is a critical nutrient in helping to maintain cognitive function, as one of its primary roles is to aid in the formation of myelin, the insulation that lines nerve cells, such as brain cells. It’s also a key nutrient in a process called methylation, which helps control the expression of genes and proteins that are involved in many important chemical pathways in the body. An imbalance in methylation may also play a role in cancer development.

Deficiency of vitamin B12 is most commonly observed in older adults, partly because of dietary changes (less meat intake), but also as the result of impaired absorption. When foods containing vitamin B12 (e.g., meat) are eaten, intrinsic factor, a substance secreted by cells in the stomach, binds to vitamin B12. That compound travels to the end of the small intestine, where it separates and vitamin B12 is absorbed. If for some reason the stomach or gastrointestinal tract is damaged (e.g., as in atrophic gastritis) or stomach acid production is slowed (e.g., with medications such as proton pump inhibitors), this multi-step absorption process may be interrupted.

Once vitamin B12 is absorbed, utilization in the body and methylation pathways may also be impaired by the presence of heavy metals, such as mercury, lead, and aluminum.

Several laboratory measures are used together (by thorough practitioners) to test for vitamin B12 deficiency, including:

• Serum vitamin B12
• Methylmalonic acid (MMA)
• Homocysteine

In a recent paper published in the American Journal of Clinical Nutrition, researchers found that high MMA values (suggestive of vitamin B12 deficiency) were associated with significantly lower scores on a standard cognitive assessment tool, especially in the areas of language comprehension and expression.

Low serum folic acid levels also were associated with poorer cognitive function scores. Folic acid, along with vitamin B12, is essential in the proper functioning of methylation pathways, which often are not working correctly in conditions such as cognitive decline, autism, and ADD/ADHD.

Lest you think that these deficiencies only affect a small percentage of people, 43 percent of the non-demented individuals age 69 and older in the study had MMA values that suggested significant vitamin B12 deficiency.

It’s critically important to make sure that both vitamin B12 and folate levels are maintained at adequate levels to reduce the risk of cognitive decline. You can learn more about treatment approaches for preventing and slowing cognitive decline here.

This entry was posted on Thursday, January 11th, 2007 at 11:42 pm and is filed under Cancer, Cognitive Decline, Vitamins. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.