There are many vitamins that get alot of publisity, however vitamin C is one of the most well know. Vitamin C plays a huge role as and antioxidant, gaurding against oxidative damage, as well as an important vitamin in maintaining connective tissue integrity. Vitamin C is a water soluble vitamin water is the main source of transport, and if you take to much, you will just get rid of it with the extra water in your system. Due to the fact that crossfit places your body under significant oxidative stress because of the high intensity, this vitamin may be a beneficial supplement to take if you do not already take it in another supplement. Here are a few great research articles on the effectiveness of vitamin C.