This lesson is better understood by going back and reading the Basic Definitions lesson.
It is a mistake to think of vitamins as little bits of energy. The only thing that provides energy for our body is the protein, carbohydrate, and lipids we eat, then only after our body has "processed" them. Vitamins are what are used to allow this "processing" to occur.
We need ATP in our body to have energy, which was covered in a previous lesson. This molecule creates energy when a chemical reaction occurs that breaks the bonds holding it together. The B vitamins play a role in this chemical reaction by carrying electrons and/or atoms to cause it to occur. The name for something that does that is a coenzyme. The various B vitamins help one or more of proteins, carbohydrates, or lipids to break down and eventually create ATP.
Here is an actual progression of these vitamins working together to get to ATP.
Vitamins B3 (Niacin) and B7 (Biotin) helps break down a glucose molecule. At the same time, more Niacin and Biotin, along with Vitamin B2 (Riboflavin) and Vitamin B5 (Pantothenic Acid) are helping to break up a fatty acid chain. Vitamin B1 (Thiamin), Riboflavin, and Pantothenic Acid take the resulting carbon atoms from these two processes and combine them. While this has been happening, even more Niacin, Riboflavin, Biotin, and Pantothenic acid have been working on amino acids. When the carbon atoms and product of the amino acid breakdown combine, even more of these B vitamins are doing that work. Then, chiefly Niacin and Riboflavin work on the conversion that produces a molecule of ATP. As you can see, there are lots of B vitamins, working together to create a molecule of energy.
Here are how some of the other vitamins work in the body:
B vitamins have to have other B vitamins in order to allow ATP to be processed. The B vitamins are water soluble, meaning they need water to be absorbed by, carried thru, stored in, and removed from the body.