637 A FUNCTIONAL MEASURE OF VITAMIN E VALIDATED

A sensitive, standardized method of measuring a biological function of vitamin E(E) is needed to define a protective E level. We therefore evaluated the release of thiobarbituric acid reacting substances(TBARS) from red blood cell(RBC) membranes after paired incubations in buffered H2O2, pH 7.4, alone and with azide to promote maximal release. TBARS was quantitated spectro-photometrically. Values were expressed as the ratio of TBARS release without azide/maximal release × 100 (%TBARS). Individual fasting plasma lipid levels were added to give total lipids(TL). Three groups were compared: A) E sufficient noncholestatic children (N=14); B) E sufficient noncholestatic adults (N=6); C) E deficient cholestatic children (N=11).