Study	Reason for exclusion
Homola 2017	A comparison of two types of vitamin E supplement and not a comparison of vitamin E to control.
Jacquemin 2009	Compares bioavailability of preparations, no placebo or control arm.
Kerem 2009	It is not a study of vitamin E supplementation compared to placebo or control.
Munck 2010	Lack of placebo or control group.
Nasr 1993	Compares two preparations of vitamin E, no control or placebo group.
Papas 2007	Compares bioavailability of preparations, no control group.
Sagel 2011	Not a randomised or quasi‐randomised study.
Thomas 1995	Comparison of vitamin E given with placebo to vitamin E given with ursodeoxycholic acid in a single participant.
Winklhofer‐Roob 1992	No placebo or control group. Compared 3 preparations of vitamin E to baseline status.
Winklhofer‐Roob 1996	Compared levels of vitamin E after supplementation with 3 different preparations of vitamin E and compared to matched controls.
Wood 2003	Compared low‐dose to high‐dose supplements. No placebo or control group.