IU (international unit)
An international unit (IU) is an internationally accepted amount of a substance. This type of measure is used for the fat-soluble vitamins (such as vitamins A, D and E) and certain hormones, enzymes, and biologicals (such as vaccines).
The definition of an international unit (IU) is generally arbitrary, technical, and eminently forgettable. For example, an IU of vitamin E is the specific biological activity of 0.671 milligrams of d-alpha-tocopherol. Nonetheless, most IUs are quite handy and helpful in use as a means of standardizing measures.
All international units are officially defined by the International Conference for Unification of Formulae.
Read Also:
- IUD (intrauterine contraceptive device)
A device inserted into the uterus (womb) to prevent conception (pregnancy). The IUD can be a coil, loop, triangle, or T in shape made of plastic or metal. An IUD is inserted into the uterus by a health-care professional. Of two types of IUDs approved in the U.S., one can remain in place for 10 […]
- IUGR
Intrauterine growth retardation.
- IV (intravenous)
“The glucose was given intravenously.” The word “intravenous” as a noun refers to an intravenous fluid drip, a solution (usually a balanced electrolyte solution) administered directly into the venous circulation. Also called a drip.
- IVC
1. Intravenous cholangiogram, an X-ray study of the gallbladder. 2. Inferior vena cava, the largest vein coming up below the heart to it. As an IVC filter.
- Iodine deficiency
A lack of sufficient iodine in the diet, which can lead to inadequate production of thyroid hormone (hypothyroidism) and enlargement of the thyroid gland (goiter). Since the addition of iodine to table salt became common, iodine deficiency has rarely been seen in the US.