Abbreviations are the same for both the singular and plural forms
International Units
In pharmacology an International Unit is the quantity of a
substance, such as a vitamin, hormone, or toxin, that produces a
specified effect when tested according to an internationally
accepted biological procedure. For certain substances, the IU has
been identified with a weight of a particular purified form of the
material.
For Vitamin A, 1 i.u. = 0.3 µg retinol, 3.6 µg b-carotene, or 7.2 µg
other vitamin A carotenoids
For Vitamin D, 1 i.u. = 0.025 µg cholecalciferol
For Vitamin E, 1 i.u. = 0.67 µg natural a-tocopherol (different
conversion factors are used for different forms of vitamin E)
Equivalent
milliliter
1/10th of a liter; 100 milliliters
0.0353 of an ounce
64.8 mg (in use 60 or 65 mg)
see below
2.2 pounds
1.05 quarts
1/1000th
1/millionth of a gram
1/1000th of a gram
1/1000th of a liter
1/billionth of a gram
1/trillionth of a gram
1/trillionth of a mole
each