There are different types of B vitamins, which are generally found together as they work in conjunction with one another. B vitamins are water soluble with limited storage capacity, which means that you need most of them on a daily basis.
Deficiencies can occur fairly readily during fasting or dieting, or with excessive intake of alcohol, sugar, refined or processed foods as well as prolonged stress. Some can be made in the body by microorganisms in the large intestine but they are also found together in many foods – so best sources are listed in this article and you can make your own, as well as explaining the role of each vitamin B.