Natural Vitamin E vs. Synthetic E

In a study published in the April 1998 American Journal of Clinical Nutrition, North American men and women were given vitamin E supplements over a period of five days. Later, their blood levels of vitamin E were tested and researchers found that twice as much natural E (d-alpha-tocopheryl) had been absorbed into the blood compared to synthetic E (dl-alpha-tocopheryl).

"What we found was that, first in blood and then eventually in organ levels, levels of natural vitamin E were almost double those of synthetic vitamin E, and they were consistently so," said Graham W. Burton, Ph.D., principal researcher at the National Research Council of Canada, Ottawa.

"Both forms of vitamin E are absorbed equally well through the gut, but the liver clearly prefers the natural form, transferring it to lipoproteins to be transported through the blood for deposition into the tissues," Burton said. "The natural vitamin E is retained by a two-to-one ratio over the synthetic."

In an earlier study (American Journal of Clinical Nutrition, 1998), researchers found that pregnant women transfer natural vitamin E to their babies more than three times more efficiently than synthetic vitamin E.