None of the 14 known vitamins supply calories so they will not give you more energy. Some vitamins do help the body use energy. However, these vitamins are easily supplied by a normal diet. Large doses of vitamins won't give you more energy. In fact, if you consume more of the vitamins like vitamin C or B, the water-soluble vitamins than your body needs, they will be simply flushed out in your urine. If you consume more vitamins A, D, E & K (the fat-soluble vitamins) than you need, they will be stored in your fat cells. Too much of these vitamins can be toxic. Be sure to read the label on the back of your vitamin bottle. When used correctly they are safe.

Additional Resources:

http://www.eatrightontario.ca/en/ViewDocument.aspx?id=43
http://edis.ifas.ufl.edu/fy470