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Vitamin E is not one single compound, rather a group of several related compounds. This section describes the various forms of Vitamin E.
General Notes on Vitamin E Forms
All natural forms of Vitamin E occur in their "D" stereoisomer form. Natural forms of Vitamin E are absorbed and retained better than synthetic forms of Vitamin E.
Synthetic Vitamin E is a mixture of eight stereoisomers, and is designated DL-Alpha-Tocopherol. Only one of the eight stereoisomers (12.5%) in synthetic Vitamin E is identical to d-Alpha-Tocopherol. The other seven have varying biological activity, ranging from 21% - 90% as active as d-Alpha-Tocopherol. Synthetic Vitamin E is absorbed and retained far less efficiently than natural Vitamin E.
Forms of Vitamin E
d-Alpha-Tocopherol (also known as Natural Source Vitamin E) is the form of Vitamin E that is most commonly found in Vitamin E supplements. This "natural" form of Vitamin E is more costly to isolate, concentrate, and manufacture than dl-Alpha-Tocopherol is to synthesize from petrochemicals and is therefore approximately twice as expensive as synthetic Vitamin E. It has 1.4 times more Vitamin E IU activity compared to synthetic Vitamin E and is retained within the body far more efficiently than synthetic Vitamin E. Each 1 mg of D-Alpha-Tocopherol possesses 1.49 IU of Vitamin E activity. Alpha-Tocopherol is the major Tocopherol in human Blood Plasma - it accounts for 87% of the total Tocopherols concentration of human Blood Plasma.
d-Alpha-Tocopherol Acid Acetate (also known as Natural-Source Vitamin E Acetate; Tocopherol Acetate; Tocopheryl Acetate) is the d-Alpha-Tocopherol form of Vitamin E combined with Acetic Acid to improve its water-solubility. It is an esterified form of Vitamin E. d-Alpha-Tocopherol Acid Acetate is not topically bioavailable (as Digestive Enzymes absent from the Skin are required for its activation). Each 1 mg of d-Alpha-Tocopherol Acetate possesses 1.36 IU of Vitamin E activity. After its absorption into the body, d-Alpha-Tocopherol Acetate, the Acetate molecule is stripped off to re-form d-Alpha-Tocopherol (by endogenous Esterase enzymes) Some researchers regard d-Alpha-Tocopherol Actetate (together with d-
Alpha-Tocopherol Succinate) as the preferable form of oral d-Alpha-Tocopherol supplementation as it is more stable than "free" d-Alpha-Tocopherol.
d-Alpha-Tocopherol Acid Succinate (also known as Tocopherol Succinate; d-Alpha Tocopheryl Succinate) is the d-Alpha-Tocopherol form of Vitamin E combined with Succinic Acid to improve water-
solubility. It is an esterified form of Vitamin E. d-Alpha-Tocopherol Acid Succinate is not topically bioavailable (as Digestive Enzymes absent from the Skin are required for its activation). Each 1 mg of d-
Alpha-Tocopherol Acid Succinate possesses 1.2 IU of Vitamin E activity. After its absorption into the body, d-Alpha-Tocopherol Succinate, the Succinate molecule is stripped off (by endogenous Esterase enzymes) to re-form d-Alpha-Tocopherol Some researchers regard d-Alpha-Tocopherol Succinate (and d-Alpha-
Tocopherol Acetate) as the preferable form of oral d-Alpha-Tocopherol supplementation as it is more stable than "free" d-Alpha-Tocopherol. The disadvantage of this form is that it is slower to increase Blood levels of Vitamin E compared to other forms of Vitamin E (although with long-term use, Blood levels of Vitamin E using this form DO "catch up").
d-Alpha-Tocopheryl Polyethylene Glycol 1000 Succinate (also known as TPGS) is d-Alpha-Tocopherol Succinate bound to Polyethylene Glycol. The advantages of this form of Vitamin E are that it is water-
soluble and can be absorbed by persons who are unable to absorb the other fat-soluble forms of Vitamin E. TPGS is a useful form of Vitamin E supplementation for Cholestasis patients and for persons who have Liver ailments that prevent the production of Bile. It is also the preferred form of Vitamin E supplementation for Crohn's Disease, Ulcerative Colitis and Acquired Immune Deficiency Syndrome (AIDS) patients.
dl-Alpha-Tocopherol (also known as all-rac-Tocopherol) is a form of synthetic Vitamin E. The stability of this form of Vitamin E at room temperature is limited. Each 1 mg of dl-Alpha-Tocopherol possesses 1.10 IU of Vitamin E activity.
dl-Alpha-Tocopherol Acetate (also known as dl-Alpha-Tocopheryl Acetate) is a synthetic form of (the Alpha-Tocopherol form of) Vitamin E bound to Acetic Acid. This form of Vitamin E is not suitable for topical application as the Skin does not contain the Esterase enzymes that are required for its reconversion to dl-
Alpha-Tocopherol. Each 1 mg of dl-Alpha-Tocopherol Acetate possesses 1.0 IU of Vitamin E activity. Its chemical formula is C31H52O3. Its molecular weight is 472.8.
dl-Alpha-Tocopherol Succinate (also known as dl-Alpha-Tocopheryl Succinate) is a synthetic form of (the Alpha-Tocopherol form of) Vitamin E bound to Acetic Acid. This form of Vitamin E is not suitable for topical application as it may encourage the development of Skin Cancer (according to a recent laboratory study). Each 1 mg of dl-Alpha-Tocopherol Acetate possesses 1.0 IU of Vitamin E activity.
d-Beta-Tocopherol is a natural form of the Beta-Tocopherol form of Vitamin E. 1 mg of D-Beta-
Tocopherol possesses 0.6 IU of Vitamin E activity.
d-Gamma-Tocopherol is a natural form of the Gamma-Tocopherol form of Vitamin E. 1 mg of d-Gamma-
Tocopherol possesses 0.15 IU - 0.45 IU of Vitamin E activity.
d-Delta-Tocopherol is a natural form of the Delta-Tocopherol form of Vitamin E. Each 1 mg of d-Delta-
Tocopherol possesses 0.015 IU of Vitamin E acitivity.
Eta-Tocopherol is a little-known form of Vitamin E.
Epsilon-Tocopherol is a little-known form of Vitamin E.
Zeta-Tocopherol is a little-known form of Vitamin E.
Mixed Tocopherols is a term used to describe Vitamin E supplements that contain a mixture of the various forms of Vitamin E. Most mixed tocopherols supplements are comprised of 80% d-alpha-
tocopherol + 20% of other forms of Vitamin E (usually d-alpha-tocopherol + d-beta-tocopherol + d-delta-
tocopherol + d-delta-tocopherol).
Source: In-Tele-Health © 2006 (from Hyperhealth CD-ROM) with kind permission
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