How much is 400 units of vitamin E?
•
3 min read
According to the NIH Office of Dietary Supplements, 400 IU of vitamin E is equivalent to either 268 mg of natural-source vitamin E (d-alpha-tocopherol) or 180 mg of synthetic vitamin E (dl-alpha-tocopherol). This variation exists because the term "international units" (IU) is a measure of biological activity, not a standard weight. Understanding this difference is crucial for anyone taking vitamin E supplements, as the form and dosage can significantly affect its impact and safety.