Definition of "vitamin" []

• 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. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The name of the vitamin comes from the Greek word pantos, meaning "everywhere.""
• "The term vitamin D applies to several members of a group of steroid prohormone molecules."
• "The term vitamin derives from experiments conducted early in this century, which indicated that proper nutrition was dependent upon introduction of one or several vital nitrogen-containing amines into the diet."