GLOSSARY

Vitamin E Reference Table

US/Canadian DRI reference for healthy adults age 19-50; the adult pair is male / female. Pregnancy and lactation values are for adults.

Vitamin E is a family of fat-soluble antioxidant compounds whose members do not contribute equally to the human vitamin requirement.

Vitamin E has eight natural forms: alpha, beta, gamma and delta tocopherols and tocotrienols. Chemical activity and retention differ. Alpha-tocopherol underlies human requirement references, so simply adding every form's mass or counting ingredient names does not necessarily reveal the amount meeting that requirement; the measurement convention and declared forms need identification.

After E forms are absorbed, hepatic transfer proteins preferentially return alpha-tocopherol to circulation, while other forms are metabolised differently. A high dietary amount of another member therefore need not produce blood concentrations comparable to alpha. This regulation cannot be predicted simply from antioxidant wording or an oil being described as natural.

Nuts and seeds in an athlete's snack provide food sources; antioxidant activity alone does not justify high-dose supplementation.