Whats bigger? IU, mg, or mcg?
1 mg (milligram) = 1,000 mcg (microgram)
So it's definitely not mcg. I own no idea what an IU is though.
IU stands for International Units and is used for the width of drugs and vitamins.
Webster's defines IU as: a quantity of a biologic (such as a vitamin) that produces a particular biological effect agreed upon as an international standard
What this scheme is that IU is dependent on the potency of the substance, and EACH substance would have a different IU to milligram conversion. For example, 1000 IU of Vitamin C would have a different weight than 1000 IU of Vitamin A
Since respectively substance would have a different conversion ratio, we CANNOT put up a conversion for IU to milligrams that covers everything, or even most things. Just too many different substances. Source(s): Welcome to OnlineConversion.com
mg is bigger than mcg
IU measures certain amount of vitamins, like vitamin E. there is no standard conversion for adjectives IU to all mg, it depends on the item in question.
see for explanation: http://www.chiro.org/nutrition/FULL/Converting_Between_IU.html