Also known as Vitamin B7 and sometimes Vitamin H it is part of the water-soluble B Group of vitamins and involved as a component of various enzymes employed in the release of energy from carbohydrates, fats, and protein. It facilitates gene expression and hence cell replication and growth. Biotin is produced naturally by gut microbes in sufficient quantity for normal requirements. It is also present in various feeds, Lucerne and Soya are apparently good sources. Horses with poor hoof horn quality may benefit from supplementation of Biotin, though studies on the rate of hoof growth have been inconclusive. Supplemented Biotin dose rate should be in the range of 3-4mg/100kg bodyweight or 15-20mg/Day for a 500 kg horse fed continuously for at least nine months.