From ‘Anti-Sterility’ to ‘Antioxidant’ to ‘Anti-Sterility’: Redirecting Vitamin E Researches towards the Old Forgotten Interest

Vitamin E is one of the types of vitamin that is not produced by the body and has to be taken orally from exogenous supply. It is found in a number of foods and plants, ranging from edible oils, wheat, rice bran, barley, oat, coconut, palm and annatto [1,2], rye, amaranth, walnut, hazelnut, poppy, safflower, maize and the seeds of grape and pumpkins. Besides, vitamin E derivatives have also been detected in human milk [3] and palm date (Phoenix canariensis) [4].

Numerous reports on the health benefits of vitamin E are widely available; however the reports of focused benefits on reproductive health are still scarce despite its nearly-100-years of discovery. Initial attempts have been made in search of new knowledge on vitamin E and reproduction, with the first ever documented report was by the founders themselves. Evans and Bishop was the first persons who reported on the finding of a particular ‘anti-sterility substance-X’ that was necessary for reproduction in 1922 [5]. Following that, the need for vitamin E in reproduction was also reported by Barrie [6] from the observations in which feeding with vitamin E deficient diet developed uterine discoloration in rats. Unfortunately from then on, studies on vitamin E have been directed towards its antioxidant properties, making it becomes a very popular lipid-soluble antioxidant.

Researches on vitamin E and reproductive health have re-emerged decades later. Scientific investigations are being actively conducted, redirecting the focus on vitamin E towards its initial interest in reproduction. Most of the current studies are emphasizing on the effects and mode of actions by vitamin E in alleviating the risks of being infertile, as well as the risks of having birth defects using laboratories animal models. The outcomes from the current studies are as summarized in Table 1.

Table 1: Summary on the current studies on the effects of vitamin E on reproduction *TOC – tocopherol, TCT – tocotrienol.

Studies on vitamin E and reproduction are being actively conducted and these are actually contributing to the effort of redirecting the interest of vitamin E studies on the reproductive health. As summarized in the paper, the vitamin E has been shown to exert beneficial effects against the reproductive-related disorders. However, many future studies are still needed to gain better understanding on the role and mechanisms of actions of vitamin E on the reproductive health before it can be considered for clinical use as an anti-sterility drug.

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