Biotin – Research studies show improvement in many horses over a period of months with biotin. Calcium – Involved in cross-linking of hoof proteins.Iodine – Acts as anti-fungal agent at higher levels. Field observations suggest oral iodine may help resolve white line disease.Organic minerals – Organic zinc and copper work with enzymes important in developing and maintaining hoof structure. Methionine/Cystine – Sulfur containing amino acids, when in the correct balance with other amino acids (i.e. lysine), can improve hoof quality and growth.