What does Iu Mean on Vitamin Labels?

If you ever buy vitamins, you might have noticed the abbreviation IU on vitamin labels and wondered what it meant. IU stands for International Unit, and it's a way to measure the amount of vitamins, hormones and other biological substances. The definition of how much is in one IU varies from vitamin to vitamin, and is set by international agreement. You can find more info at: http://en.wikipedia.org/wiki/Internation...