Depression is a mental disorder, but at some times is not treated as one. Depression is never to be taken lightly, and should always be taken very seriously.    Some symptoms of depression are:   - Lack of interest in normally enjoyable activities.
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.he 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.
The SI base units. The International System of Units (French: SystÃ¨me international d'unitÃ©s pronounced: [sistÉm ÉÌtÉÊnasjÉnal dynite]; abbreviated as SI) is the modern form of the metric system, and is the most widely used system of measurement. It comprises a coherent system of units of measurement built on seven base units.