While most of us don't suffer from outright B vitamin deficiency, everyday life imposes many nutritional threats that snatch away these nutrients. Let's look at how this happens and what you can do to guard yourself.

What are B Vitamins?
While today we know of at least 10 different B vitamins, scientists initially thought this complex of nutrients was just one vitamin. The story begins almost 100 years ago when Eijkman, a Dutch physician living in Java, was watching chickens kept by the local penitentiary. He noticed these birds bore a striking resemblance to his patients suffering from beriberi. Although Eijkman didn't know it at the time, this condition, characterized in humans by poor memory, irritability, fatigue and other symptoms, is actually caused by thiamin (or B1) deficiency. But the doctor had an inkling that diet might play a part. So he added rice bran to the fowl's otherwise bleak rations of polished rice table scraps. The experiment worked and the supplemented chickens thrived.

In the decades that followed, more information was elucidated on thiamin and its B vitamin relations: riboflavin (B2), niacin (B3), pantothenic acid (sometimes called B5), vitamin B6 (actually a group of related compounds: pyridoxine, pyridoxal, pyridoxamine and others), B12 (or cyanocobalamin), folic acid and biotin. You'll notice that some B vitamins are assigned numbers. This is because scientists labeled these compounds in numerical order of discovery. Today we normally refer to the B vitamins by chemical name.

Inositol and choline are sometimes lumped under the B complex title. Less is known about these compounds, and experts don't always agree on whether they're true vitamins or not.

A vitamin by definition is a substance that belongs to a group of unrelated organic compounds. Each vitamin is essential for good health (and sometimes life), but you only need a minuscule amount in your food for this purpose. Vitamins vary widely in chemical makeup and physiological function. For the most part, your body can't manufacture vitamins. Although for the water soluble B vitamins, small amounts of folic acid, niacin and B12 can be synthesized.

The B vitamin clan retain close ties because, like most families, they act alike, sometimes rely on one another and are found in similar foods. They're so close, in fact, that low intake of one often affects another. This means single B vitamin deficiencies are relatively rare, although deficiency symptoms of one B vitamin may predominate. For this reason, taking large amounts of a single B nutrient may create a vitamin imbalance and snowball into another B vitamin deficiency.

Why Do We Need B Vitamins?
We would literally be lost without B vitamins. Besides memory, these nutrients feed and regulate the brain and nervous system. The brain and its extensive network of nerve fibers and cells, are like a complex computer that instruct us how to react to temperature, pressure, pain and other stimuli. Neurological hookup throughout your body allows organs to function properly. As an added bonus, this complex and not-totally-understood system grants us emotion and thought.