Tocopherols (Vitamin E)
What does it do? Vitamin E is the name for a group of chemicals called "tocopherols." Tocopherols act as antioxidants for living cells, and they are an important nutrient for human health.
It seems as if Vitamin E should also work well as an antioxidant for fats, soap, lotions, etc., so many soapers add Tocopherols to their soap to prevent rancidity (DOS, Dreaded Orange Spots). Unfortunately, Vitamin E does not appear to be effective for this. Kevin Dunn, author of the book Scientific Soapmaking, found Vitamin E did not prevent oxidation of soap any better than no additive at all.
How much should I use? Vitamin E is not recommended for preventing rancidity/DOS in soap or fats.
How should I use it? Do not use it. I recommend adding rosemary oleoresin (ROE) to your soap and fats to lengthen their shelf life.