TABLE 9-1 Amounts in International Units (IU) of Any Forms of α-Tocopherola Contained in Vitamin Eb Supplements Equivalent to the UL for Adultsc

Sources of Vitamin E

Available as Supplements

UL for Adults

Total α-Tocopherol (mg/day)

IU from Source

Providing Adult UL

Synthetic Vitamin E and Esters

   

dl-α-Tocopheryl acetate

1,000

1,100

dl-α-Tocopheryl succinate

1,000

1,100

dl-α-Tocopherol

1.000

1,100

Natural Vitamin E and Esters

   

d-α-Tocopheryl acetate

1,000

1,500

d-α-Tocopheryl succinate

1,000

1,500

d-α-Tocopherol

1,000

1,500

a All forms of supplemental α-tocopherol include all eight stereoisomers of α-tocopherol. The UL was based on animal studies feeding either all racemic- or RRR-α-tocopherol, both of which resulted in equivalent adverse effects.

b Vitamin E supplements have historically although incorrectly been labeled d- or dl-α-tocopherol (Horwitt, 1976). Sources of vitamin E include the all racemic- (dl-α-tocopherol [RRR-, RRS-, RSR-, RSS-, SSS-, SRS-, SSR-, and SRR-] or synthetic) form and its esters and the RRR-α-tocopherol (d-α-tocopherol or natural) form and its esters. All of these forms of vitamin E may be present in supplements.

c Conversion factors given in Table 6-1 to determine equivalency for meeting requirements are not directly applicable as they take into account lack of documented biological activity of 2S-forms of α-tocopherol in meeting requirements. The conversion factors used in this table are based on 2S-forms contributing to the adverse effects identified.

ble to estimate α-tocopherol intakes by multiplying the total α-TE in food (obtained from food composition tables) by 0.8. Also, the form of chemically synthesized α-tocopherol in fortified foods, multivitamin supplements, and vitamin E supplements has to be identified so that appropriate adjustments for activity can be made before calculating total intake of α-tocopherol.

Selenium

Dietary intakes of selenium depend on the selenium content of the soil where the plant was grown or the animal was raised. Food animals in the United States and Canada usually have controlled diets to which selenium is added, and thus, the amounts found in muscle meats, milk, and eggs are more consistent than for plant foods.



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement