Monograph: Evening Primrose Oil

Help on accessing alternative formats, such as Portable document format (PDF), Microsoft word and PowerPoint (PPT) files, can be obtained in the alternate format help section.

Monograph: Evening Primrose Oil (English) (PDF version - 49 K)
Get Adobe® Reader®
Vitamin E is an optional medicinal ingredient in evening primrose oil products. However, no use or purpose statements may be associated with vitamin E. See Appendix 1 for vitamin E proper name, common name, source material, and dose information.
Date: 2018-09-25

NHPID name

Evening Primrose Oil ( Germplasm Resources Information Network Taxonomy )

Proper name(s)

Common name(s)

Evening Primrose Oil

Source material

Route Of administration

Oral

Dosage form(s)

Use(s) or purpose(s)

Statement(s) to the effect of:

Dose(s)

Duration of use

No statement is required

Risk information

Statement(s) to the effect of:

Caution(s) and Warning(s): No statement is required Contraindication(s): No statement is required Known Adverse Reaction(s): No statement is required

Non-medicinal ingredients

Specifications

References cited

References reviewed

Appendix 1: Vitamin E

Proper name(s), common name(s), and source material(s)

Table 1: Vitamin E proper names, common names and source materials
Proper name (s) Common name(s) Source material(s)

Vitamin E (Sweetman 2007; IOM 2003; O'Neil et al. 2001)

Alpha (α)-tocopherol (Sweetman 2007; O'Neil et al. 2001); Vitamin E (Sweetman 2007; IOM 2003; O'Neil et al. 2001)

All racemic (all rac)-α-tocopherol/ dl-α-tocopherol (Sweetman 2007; IOM 2003)

All rac­-α-tocopheryl acetate/ dl-α-tocopheryl acetate (Sweetman 2007; IOM 2003)

All rac­-α-tocopheryl succinate/ dl-α-tocopheryl acid succinate/ dl-α-tocopheryl succinate (Sweetman 2007)

RRR-α-tocopherol/ d-α-tocopherol (Sweetman 2007; IOM 2003; O'Neil et al. 2001)

RRR-α-tocopheryl acetate/ d-α-tocopheryl
acetate (Sweetman 2007; IOM 2003)

RRR-α-tocopheryl succinate/ d-α-tocopheryl acid succinate/ d-α-tocopheryl succinate (Sweetman 2007; IOM 2003)

Quantity:

The quantity of vitamin E must always be provided in terms of α-tocopherol (AT) (i.e. mg RRR-α-tocopherol), irrespective of the source material used.

IUs may be provided as optional additional information on the PLA form in the "potency" field and on product labels.

Table 2: Dose information for vitamin E presented as dose per day (IOM 2006)
Subpopulation Vitamin E (mg AT/day)
Minimum Maximum
Adults
≥ 19 y
4.5
179

Conversion factors:

Table 3: Conversion of vitamin E source material quantity into vitamin E quantity in terms of alpha-tocopherol (AT) and vitamin E activity in terms of International Unit (IU) (IOM 2006)
Source material
(1 mg)
Vitamin E quantity
(mg AT)
Vitamin E activity
(IU)
RRR-α-Tocopherol
1.00
1.49
RRR-α-Tocopheryl acetate
0.91
1.36
RRR-α-Tocopheryl succinate
0.81
1.21
All rac-α-tocopherol
0.50
1.10
All rac-α-tocopheryl acetate
0.46
1.00
All rac-α-tocopheryl succinate
0.41
0.89
Table 4: Conversion of vitamin E source material activity into vitamin E quantity in terms of alpha-tocopherol (AT) (IOM 2006)
Source material
(1 IU)
Vitamin E quantity
(mg AT)
RRR-α-Tocopherol
0.67
RRR-α-Tocopheryl acetate
0.67
RRR-α-Tocopheryl succinate
0.67
All rac-α-tocopherol
0.45
All rac-α-tocopheryl acetate
0.45
All rac-α-tocopheryl succinate
0.45

Examples using the vitamin E conversion factors:

  1. Converting vitamin E activity into quantity of AT (mg)

    Convert 400 IU of RRR-α-tocopheryl succinate activity into mg AT:
    = 400 IU x 0.67 mg AT/IU
    = 268 mg AT

  2. Converting vitamin E source material quantity into quantity of AT (mg)

    Convert 200 mg of all rac-α-tocopheryl acetate into mg AT:
    = 200 mg x 0.46 mg AT/mg
    = 92 mg AT