Taurine is one of the lessor known sulphur amino acids, and can be synthesised by the body form cysteine as long as vitamin B6 is present. It plays a variety of roles in the normal functioning of the brain, heart, gallbladder, eyes and vascular system.
Taurine serves as a neurotransmitter in the brain, a stabiliser of cell membranes and a facilitator in the transport of ions such as sodium, potassium, calcium, and magnesium. It is the second most important inhibitory neurotransmitter in the brain. The amino acids alanine, glutamic acid and pantothenic acid inhibit taurine metabolism, while vitamins A and B6, zinc and manganese help to synthesise taurine. Cysteine and vitamin B6 are the nutrients most directly involved in taurine synthesis. The gallbladder utilises taurine for the formation of taurocholic acid, one of the two primary bile acids necessary for the breakdown of fats in the small intestine. Taurine is also involved with bilirubin and cholesterol excretion in bile.
Taurine is one of the most popular ingredients in energy drinks, although there is little scientific data to support this use. A high consumption of alcohol will increase an individuals loss of taurine. Low levels of taurine are often found in those on a vegetarian diet too. Lately, cosmetic compositions containing taurine have been introduced, as it also helps to maintain skin hydration.