WHAT IS AN INTERNATIONAL UNIT?
IU stands for International units and is a unit commonly used in the measurement of medications, vaccines and vitamins.
The volume or mass that makes up one International unit is dependent on the concentration or potency of the substance and therefore varies from substance to substance depending on what is being measured.
This means that converting between international units and micrograms or milligrams is not a simple calculation and we can’t provide a converter to do this calculation for you (sorry about that). The exact measure of one IU of a substance is in fact established by international agreement for each substance 1.
HOW TO FIND OUT THE CONVERSION VALUE?
If you want to find out how many micrograms (mcg) or milligrams (mg) are in one IU of your medication, you could contact your pharmacist to find out. As an alternative, you could try contacting the drug manufacturer directly. For a vitamin, consider contacting the vitamin manufacturer - their contact information is usually listed on the bottle.