Sulphur is a chemical element. In the body, sulphur is part of the amino acids cysteine and methionine. These amino acids are referred to as sulfur-containing amino acids, and they are represented in practically all proteins that makes up the body. Sulphur is among others also part of the B-vitamins thiamine (vitamin B1) and biotin, the natural anticoagulant heparin, and chondroitin sulfate, an important constituent of cartilage in all joint surfaces.
Horses cover their requirements for sulphur through intake of organic, sulfur-containing feed molecules, mainly the amino acids methionine and cysteine.
When the ration has sufficient amounts of protein, preferably from several sources, sulphur deficiency will not occur.