This may appear to be arcane nutritional chemistry, but it is key to understanding how the body absorbs natural and synthetic supplements differently. Molecular structure determines how the body uses vitamin E. Researchers have found that natural vitamin E assimilates far better than synthetic versions. Specific binding and transport proteins produced in the liver select the natural d-alpha form of vitamin E and largely ignore all other forms.
In one experiment, Japanese researchers alternately gave natural and synthetic vitamin E to seven healthy young women. It took 300 mg synthetic vitamin E to equal the blood levels achieved by a 100-mg dose of natural vitamin E. chiro Natural vs. Synthetic Vitamin E