An evaluation of biological effects of different forms of vitamin E.

A chance observation that some forms of vitamin E are cytotoxic in cell culture. Understanding of vitamin E metabolism is important since plant genetic engineering is changing the composition of plant vitamin E. In some cases, the form being engineered may not be appropriate.

We have completed an evaluation of the vitamin E in cultured cells. We have shown that some forms are cytotoxic while others are not. The cytotoxic forms are the same forms that are eliminated by the body. The mechanism of cytotoxicity appears to involve the unfolded protein response (UPR) but is not dependent upon it. Cells from mice with a defective UPR show similar sensitivity.

As a result of our current and past efforts, we now know that some forms of supplemental vitamin E possess a potential of untoward biological effects. This information changes considerably our perspective of ingesting purified supplements. It is very unlikely that the concentrations we employed in vitro can ever be achieved in vivo largely because of a “system” that selectively degrades/excretes most forms of vitamin E. However, it is plausible that some individuals may possess a less robust “system." Under these circumstances, our information may be relevant.

Hatch

Robert Parker