Antivitamins are:
a) Any of various fat-soluble or water-soluble organic substances essential in minute amounts for normal growth and activity of the body and obtained naturally from plant and animal foods
b) Substances that prevent vitamins from exerting their typical metabolic effects
c) Any of numerous proteins or conjugated proteins produced by living organisms and functioning as specialized catalysts for biochemical reactions
d) Nonprotein organic substances that usually contain a vitamin or mineral and combine with a specific apoenzyme to form an active enzyme system
