Actually you do not need an Rx for any of this. Some believe that B12 does the energy thing. But in our bodies it is seldom any single vitamin or whatever acting alone. When you get your particular nutrient from a food source rich with it - say C from oranges or whatever, there is evidence that there are micro phytonutrients that act synergistically with the main ingredient that actually make it work better, be absorbed easier, etc. This can get very complex when you consider all the possible interactions, some vitamins only are absorbed well when taken with a particular other vitamin or nutrient..... not as easy as just taking B12 when you really look at it. The main OCF web site goes into all these aspect of nutrition in detail. Start on the facts page and work your self deeper into the sublinks.