Declaring natural vs. synthetic vitamin E on the new Supplement Facts label

CRN Member query:

"We have a question regarding the new labeling regulations and are hoping you can help. Specifically, since we will be labeling vitamin E content in milligrams instead of international units, how do we declare natural and synthetic vitamin E in the Supplement Facts box?”

CRN's Andrea Wong responds:

Regarding the specifics of vitamin E, naturally-sourced vitamin E is “RRR-alpha-tocopherol” or “d-alpha-tocopherol.”  The synthetically produced form is “all rac-alpha-tocopherol” or “dl-alpha-tocopherol.”

Conversions are as follows: 

• 1 mg alpha-tocopherol = 1 mg RRR-alpha tocopherol = 2 mg all rac-alpha tocopherol
• 1 IU RRR-alpha tocopherol = 0.67 mg alpha tocopherol
• 1 IU all rac-alpha-tocopherol = 0.45 mg alpha tocopherol
• RRR-alpha tocopherol = D-alpha tocopherol
• all rac-alpha tocopherol = DL-alpha tocopherol

With respect to vitamin E, FDA stated in the proposed rule for food and supplement labeling that all rac-α-tocopherol acetate in fortified foods or dietary supplements has one-half the activity of RRR-α-tocopherol naturally found in foods or the 2R stereoisomeric forms of α-tocopherol. CRN included in its comments to the proposed rule a request for FDA to include this same information as a conversion factor in the final regulation. FDA agreed and in the 2018 final rule, it included the following conversion factors:

1 mg alpha-tocopherol = 1 mg RRR-alpha tocopherol = 2 mg all rac-alpha tocopherol

On the label, the quantity of vitamin E is required to be listed in mg in the Supplement Facts box. The form of vitamin E may be listed in parentheses next to vitamin E in the box, but if it is not, it must be disclosed in the ingredient list below the box. 

For examples—which will apply to many nutrients—please see this link from FDA.