Definition of "menadione" []

• A yellow crystalline powder, C11H8O2, used in medicine as a vitamin K supplement. (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 third tye of vitamin K, menadione, is not made in nature so is therefore manmade."
• "While this form of vitamin K can sometimes be converted by the body into non-toxic forms, research studies have shown unwanted risk stemming from intake of menadione."
• "Food and Drug Administration (FDA) does not allow vitamin K to be sold as a dietary supplement in its menadione form."