Most of us look for high potency products when shopping for supplements, and with vitamin E this can be a mistake. One reason is the potency measurement for vitamin E was developed in 1944, about 70 years ago. Sure this is out of date, but there’s more to consider. The test measures female rat fertility to assess the potency (as international units) and only the commercial form of vitamin E measures high in international units (iu).
It is estimated that most Americans do not consume the recommended amount of vitamin E. This even takes into account that many cereal products are fortified with the vitamin. The recommended amounts for vitamin E range from 15iu to 30iu. Most vitamin E products on the market today supply from 100 to 400iu of vitamin E “activity.”
400iu may seem like a lot, but what’s the harm in such a high intake? After all, it’s just a vitamin. Truth is it’s hard to say what the harm may be, if any. Recent studies show there may be small increase in mortality in those who consume these amounts. There is a lot of argument about these studies, but considering we are trying protect and enhance, why argue?
The question should be how this high dosage might do harm? There is one explanation that has been gaining evidence for over 10 years, but has very little focus in consumer literature. This is that a natural balance between the vitamin E isomers that has existed naturally in our diets is important for human health. Research documents a natural competition between the vitamin E isomers and enhanced intake of one will limit the functionality of the others.
This is very important information because we are just starting to discover the unique actions of the different vitamin E isomers. We now know that gamma tocopherol provides unique antioxidant protection against one of the most damaging oxidative reactions.
The scientific focus to gain knowledge of all of the vitamin E isomers is limited. What we do know is that the function of vitamin E is very important to health and longevity, and that altering the natural ratio of the vitamin E isomers has its consequences.