B vitamins work together and are commonly called B-Complex. The symptoms of deficiency include inflamed skin, digestive problems, and mental impairment.
B vitamins are essential for converting the food you eat into usable energy. Deficiencies used to be rare, seen mostly in vegetarians who don’t enough of the foods containing B vitamins, and alcoholics who have depleted their vitamin B reserves. Now, as more people are converting to vegetarian diets, deficiency is increasing.
The combination of iron, b vitamins, and zinc is a powerful stress fighter. Folic acid, or B9 with B12 have recently been tied to preventing and even possibly reversing macular degeneration and Alzheimer's.
B vitamins are water soluble, so your body discards what it doesn't need.
B complex is sort of, well... complex. You'll find the details of each B Vitamin in the Vitamin listings-