Auburn, Feb. 9--The next time an elderly friend or relative displays a lapse in mental ability, don’t assume the worst.

While it’s quite possible such lapses may stem from aging, they may instead be symptoms of a chronic vitamin deficiency.

B vitamins, especially pyridoxine (B-6), cobolamin (B-12) and thiamin (B1), are believed to play a key role in brain function. People, especially the elderly, who lack significant amounts of B-12, for example, may pay dearly with impaired brain function.

"Studies have shown B vitamins work with enzymes that control the neurochemicals that move between nerves within the brain," says Dr. Robert Keith, and Alabama Cooperative Extension System nutritionist. "Some of them even may influence the physical integrity of the nerves."

Nerves are encased with a fatty covering known as the myelin sheath that must remain intact in order for the nerves to function properly. Studies have shown inadequate levels of B-12 in the body actually may compromise the integrity of this covering, Keith says.

"If you’re deficient in B-12, the sheath may become undone so that the nerve can’t send impulses in a normal way," Keith say. "You don’t think as well after that happens."

Nutritionists believe a surprising percentage of senior citizens -- roughly 15 percent – could be B-12 deficient to some degree. Many elderly people, in fact, can’t absorb the vitamin from their food and may need to take supplements or receive injections of B-12 from their doctor.

As a result, what is commonly attributed to aging or, even worse, mild strokes, in some cases actually may be caused by this deficiency of this key vitamin. While B-12 and other B vitamins appear to play a direct role in mental agility, other vitamins may play an equally vital, though indirect, role.

As people age, for example, there is a greater likelihood of fatty substances in the bloodstream attaching to arterial walls and undergoing a process known as oxidization. As this process occurs, plaque, a natural byproduct of oxidization, forms along arterial walls, eventually obstructing blood flow to the brain.

However, studies have shown so-called "antioxidant" vitamins, such as C and E, may work indirectly to prevent oxidization from occurring in the first place. Antioxidants seem to be effective even in instances where impaired brain function already has occurred.

While University of Hawaii researches failed to detect any evidence that vitamins C and E actually prevent strokes from occurring, they do believe these two vitamins may act as a safeguard against vascular dementia by limiting brain damage after a stroke occurs.

Even so, Keith says there are plenty of other reasons why people should consume foods containing ample amounts of these two vitamins, since both appear to safeguard against several other diseases that typically occur late in life.

"If you maintain a good intake of vitamins C and E over the long haul, you’re not only going to reduce your risk of cardiovascular disease but of cancer and cataracts as well," he says.

While the positive effects of these vitamins may not be evident for many years, Keith says many people who consume good daily amounts of vitamins C and E are likely to reap big dividends late in life.

"It's an extremely subtle thing that may not be noticed for as long as 30 years," Keith says. "Then, when you reach 60, you’ll notice you won’t have the same problems with, say, cholesterol, cataracts and high blood pressure that plague your neighbor or co-worker who is the same age."

Source:  Dr. Robert E. Keith (rkeith@acesag.auburn.edu), Alabama Cooperative Extension System nutritionist.