Whether people take natural or synthetic forms of vitamin E may affect how well they retain the vitamin. And regardless of age, sex, or race, the ratio remains 2 to 1. Parker is completing a study in which he gave natural and synthetic forms of alpha-tocopherol to six people. The results have been fascinating. But when people stop taking the vitamin supplements, the ratio changes, reaching as high as 2.4 to 1 in favor of the natural form and sinking as low as 1.2 to 1 in favor of the synthetic form.
Some people can very strongly discriminate.
Other people can less strongly discriminate. The heterogeneity among people was masked as long as they took a big supply of supplements every day. Another surprising discovery for Parker was that only high doses of vitamin E result in substantial increases in blood levels of the vitamin. These high rates of supplementation are those that have been linked with reduced risks for cardiovascular disease. Low doses of vitamin E, he found, are ineffective because the body seems to have mechanisms to maintain a constant level of vitamin E in the blood.