King also advises against relying purely on carbohydrates. Ultrarunners also need fat and protein in an ultra. It is true that vitamins are lost in an ultra. Ultrarunners have requirements above and beyond the levels stated by the FDA, and mixing in some vitamins along with your food helps. Energy bars provide vitamin replacement, but examine the contents closely, as the amounts vary widely.
Vitamins play an even bigger role after an ultra race.
The immune system is weakened, thus consuming antioxidants will help ward off potential illness that sometimes follows an ultra effort. Taking vitamin C, E and beta carotene can help neutralize the free radicals that are produced when exercising or running extremely long distances. Free radicals are unstable molecules that can cause muscles to be further damaged, as well as a weakening the immune system. Amino acid supplements should in theory keep you more anabolic, versus catabolic, a state in which the body begins to break down. I have also seen people stage miraculous recoveries during the night of 24-hour runs, who, after consuming exclusively carbohydrates, have taken protein or amino acid supplements, then suddenly sprung to life.