One 8.4 fl oz. can of Red Bull Sugar free contains 80 mg of caffeine, about the same amount as in a cup of home-brewed coffee. Caffeine was widely used by ancient civilizations. It was traditionally consumed from natural sources like tea, coffee, cacao beans and cola nuts and appreciated for its stimulating effects on the human body. Vitamins are essential micronutrients that are required for maintaining normal body functions. Taurine is an amino acid, naturally occurring in the human body and present in the daily diet. It is involved in a wide range of biological processes.