Antivitamin
• Antivitamin is simply a substance that makes a vitamin ineffective.
• Ascorbic acid oxidase: is a multi-copper enzyme that catalyzes the oxidation of ascorbic acid to dehydroascorbic acid
• Thiaminases: are enzmyes found in a few plants and the raw flesh and viscera of certain fish and shellfish. When ingested these enzymes split thiamin (Vitamin B1), an important compound in energy metabolism, and render it inactive.
• Tannins: water-soluble polyphenols that are present in many plant foods. They have been reported to be responsible for decreases in feed intake, growth rate, feed efficiency, net metabolizable energy, and protein digestibility