Though it sounds like an individual nutrient, Vitamin B is actually a blend of 8 different nutrients all in the same family. In fact, you will most likely hear it referred to as the 'complex' instead of a single nutrient.
But no matter which of the chemically distinct complexes you are talking about, Vitamin B is best known as cell metabolism helper.
Because of this reputation, Vitamin B is found in an increasing amount of diet products. You will even find the specific compound B-12 available in a liquid form that you take subcutaneously- that is you put it under your tongue and let it absorb instead of swallowing like you would a traditional liquid. A good Vitamin B complex or liquid will help speed your metabolism, which can lead to weight loss.
Of course, the weight loss only comes with additional measures. That means a good, balanced diet low in fat and regular exercise including cardiovascular workouts at least 2-3 times a week. Without these extra measures, you will not see any difference in your body or weight simply by ingesting this nutrient.
When you go to the store to buy, you will want to look for a good pill form that has a freshness seal and is in the form you like best- caplet, tablet, etc. If you are buying the liquid, then try to buy in glass bottle form instead of plastic, if possible. Most come with a rubber stopper for measuring. If you do buy in a glass bottle, make sure it is a color that light can not get through easily, such as amber.
This will ensure non-spoilage and a longer shelf life. Store in a dark, dry and cool place to keep the compound the same as the day you bought it.