There are 8 different B vitamins, normally present in a well-balanced diet and are known to be beneficial for metabolism, brain chemistry, immunity and the cardiovascular and nervous systems:

B-1 Thiamine  (oatmeal, peanuts & tofu); B-2 Riboflavin (eggs, milk, lean meats & asparagus); B-3 Niacin (salmon, blueberries & sesame seeds; B-5 Pantothenic Acid (wheat germ, broccoli & shrimp) B-6 Pyridoxine (baked potato in the actual skin; bananas & peas) B-7 Biotin (nuts, cauliflower & mushrooms) B-9 Folic Acid (spinach, oranges, beans & whole grains) B-12 Cobalamin (beef, liver, cooked clams & trout)

Most of us try really hard to eat a well-balanced healthy diet, and we might still be deficient in B Vitamins.  Emotional stress and many metabolic issues can cause various illnesses or even exposure to air pollution or environmental toxins, can lead us to depleted B vitamins.  I do suggest take a B-Complex supplement daily with breakfast.