How much is 1 mcg in IU?
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3 min read
The conversion from micrograms (mcg) to International Units (IU) is not a single, universal number, but depends entirely on the specific vitamin or substance in question. For instance, 1 mcg of vitamin D is equivalent to 40 IU, while 1 mcg of vitamin A (retinol) is significantly less. This difference exists because IU measures a substance's biological activity, whereas mcg measures its mass.
