1. What is IU (International Units)?

International Units (IU) are a measurement of biological activity used for vitamins, hormones, medications, vaccines, blood products, and similar biologically active substances. The exact definition varies by substance.

2. How Does the Calculator Work?

The calculator uses the IU conversion formula:

Where:

• \( mg \) — Milligrams of the substance
• \( IU\ per\ mg \) — Substance-specific conversion factor

Explanation: The conversion factor varies by substance because IU measures biological activity rather than mass. For example:

• Vitamin D: 1 IU = 0.025 μg
• Vitamin E: 1 IU = 0.67 mg (d-alpha-tocopherol)
• Insulin: 1 IU ≈ 0.0347 mg

3. Importance of IU Conversion

Details: Accurate IU conversion is crucial for proper dosing of medications and supplements, especially when comparing products with different units or formulations.

4. Using the Calculator

Tips: Enter the amount in milligrams and the specific conversion factor for your substance (available from pharmaceutical references). Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why can't I find a standard IU to mg conversion?
A: Because IU measures biological activity, the conversion varies by substance. You must know the specific conversion factor for your compound.

Q2: Are IU and mg interchangeable?
A: No, they measure different things (activity vs. mass). Conversion is only possible with substance-specific factors.

Q3: Where can I find conversion factors?
A: Check pharmaceutical references, product specifications, or medical literature for your specific substance.

Q4: Why do some substances use IU instead of mg?
A: IU is used when biological activity is more important than mass, especially for substances with multiple forms that have different potencies.

Q5: Can I use this for all IU conversions?
A: This calculator provides the mathematical conversion, but you must use the correct substance-specific factor for accurate results.