What does IU mean?

The standard units determined through international negotiation are called "international units". International standards are mainly for countries to establish and standardize their own national standards. For drugs that have not yet formulated international standards, the state may formulate national standards.

A "unit" or an "international unit" can have its corresponding weight, but sometimes it is difficult to determine. For different drugs, the conversion between unit and weight is different.

origin

193 1 year, the vitamin Committee of the World Health Organization of the League of Nations defined the international units of various vitamins for the first time. For example, every 1 international unit of vitamin A is equivalent to 0.3 μ g, if its acetate is 0.344 μ g, vitamin P is equivalent to 0.025 μ g, vitamin E is equivalent to 1 mg, and so on. Although many vitamins are expressed by weight now, vitamins A and D are still expressed in international units.

Antibiotics are mostly expressed in units. With the development of scientific research and industry, their chemical structures have gradually become clear, and their contents can be expressed by physical and chemical methods, so they are also expressed by weight.

Refer to the above? Baidu encyclopedia -iu