Vitamin E · unit conversion
Pick the chemical form the label names, then the direction. Nothing is converted until a form is chosen, because the same number of IU is a different mass for each form.
Result
Choose a form first. IU is not a mass, so without the form there is no factor that can be said to apply.
The factors on this page
| Form | From | To | Factor | Source | Year |
|---|---|---|---|---|---|
| d-alpha-tocopherol, natural (vitamin E) | IU | mg | 0.67 | Vitamin E - Health Professional Fact Sheet (NIH Office of Dietary Supplements) | not dated |
| dl-alpha-tocopherol, synthetic (vitamin E) | IU | mg | 0.45 | Vitamin E - Health Professional Fact Sheet (NIH Office of Dietary Supplements) | not dated |
As published
To convert from IU to mg: 1 IU of the natural form is equivalent to 0.67 mg of alpha-tocopherol. [Labelling convention — a rounded figure (approx. 2/3), the reciprocal of 1.49 IU/mg; independently confirmed in FDA's guidance Table 6 for 'Natural vitamin E (RRR-alpha-tocopherol) including its ester forms (RRR-alpha-tocopheryl acetate and RRR-alpha-tocopheryl succinate)' at the same 0.67 value.]
Vitamin E - Health Professional Fact Sheet (NIH Office of Dietary Supplements)
1 IU of the synthetic form is equivalent to 0.45 mg of alpha-tocopherol. [Labelling convention — rounded reciprocal of 2.22 IU/mg; independently confirmed in FDA's guidance Table 6 for 'Synthetic vitamin E (all-rac-alpha-tocopherol) including its ester forms' at the same 0.45 value.]
Vitamin E - Health Professional Fact Sheet (NIH Office of Dietary Supplements)