Visit the
Molecular Expressions Website

Galleria
Photo Gallery
Silicon Zoo
Chip Shots
Screen Savers
Museum
Web Resources
Primer
Java Microscopy
Win Wallpaper
Mac Wallpaper
Publications
Custom Photos
Image Use
Contact Us
Search
Home

Polarized Light Digital Image Gallery

Menadione (Vitamin K)

A fat-soluble vitamin precursor, menadione is converted to menaquinone in the liver. The primary function of vitamin K in the body is to assist in normal blood clotting, but it also plays a role in bone calcification.

View a second image of menadione.

Natural sources of vitamin K are green leafy vegetables, such as spinach and kale, and some oils such as soybean oil, but it is found in lesser amounts in meats, eggs, fruits, and some dairy products. To help meet the United States Food and Drug Administration's recommended daily allowance (RDA) of 80 micrograms for adult males and 65 micrograms for adult females, enriched foods such as breakfast cereals, breads, rice, and pastas and dietary supplements are available. In the United States, many people do not meet their daily requirement, and from recent bone development research, even the RDA may be insufficient.

Phylloquinone (or phytylmenaquinone; vitamin K-1), the most common form of vitamin K, is used as a benchmark for dietary intake. The hydrogenation of vegetable oils for the grocery marketplace converts vitamin K to another formulation, dihydrophylloquinone. However, the hydrogenated version is much less biologically active than natural phylloquinone.

To a biochemist, menadione (vitamin K-3) is also known as kativ-G or 2-methyl-1,4-naphthoquinone. With a molecular weight of 172.18, a molecule features 11 carbons, 8 hydrogens, and two oxygen atoms. Vitamin K takes the form as K-2 or multiprenylmenaquinone in the intestinal flora.

Contributing Authors

Omar Alvarado, Thomas J. Fellers and Michael W. Davidson - National High Magnetic Field Laboratory, 1800 East Paul Dirac Dr., The Florida State University, Tallahassee, Florida, 32310.


BACK TO THE POLARIZED LIGHT IMAGE GALLERY

BACK TO THE DIGITAL IMAGE GALLERIES

Questions or comments? Send us an email.
© 1995-2013 by Michael W. Davidson and The Florida State University. All Rights Reserved. No images, graphics, software, scripts, or applets may be reproduced or used in any manner without permission from the copyright holders. Use of this website means you agree to all of the Legal Terms and Conditions set forth by the owners.
This website is maintained by our
Graphics & Web Programming Team
in collaboration with Optical Microscopy at the
National High Magnetic Field Laboratory.
Last Modification Friday, Aug 01, 2003 at 11:43 AM
Access Count Since September 17, 2002: 6193
Visit the website of our partner in introductory microscopy education: